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- What is a SOC 2 audit firm, and who is legally allowed to sign the report?
- Which type of SOC 2 audit firm fits your company?
- How much does each organization group cost in 2026?
- How do you verify a SOC 2 audit firm is legitimate?
- What should you ask a SOC 2 audit firm before you hire them?
- How do you compare SOC 2 audit proposals side by side?
- Which SOC 2 audit firm fits your company profile?
- Does your SOC 2 auditor need to know your GRC platform?
- Does the firm need your industry or an adjacent accreditation?
- What are the red flags that should end the conversation?
- How long does the whole engagement take?
- How we verify and rank the firms in this guide
- Common questions about choosing a SOC 2 audit firm
How should you compare SOC 2 audit firms?
Normalize the scope first, then compare price, fieldwork timing, peer-review status, signing entity, partner involvement, re-testing, and year-two terms. In the current benchmark of 48 recently verified attestation-capable records, the median Type 2 range midpoint is $43K and the p10–p90 span is $24K–$100K. Use the distribution to question an outlying proposal, not to rank a firm by price alone.
| Selection check | Current benchmark | How to use it |
|---|---|---|
| Type 2 range midpoint | $43K median; $24K–$100K p10–p90 | Ask which scope, criteria, entities, and re-testing terms explain a quote outside the span. |
| Fieldwork to report | 8 weeks median; 4 weeks–12 weeks p10–p90 | Put the observation window and report date beside the fieldwork estimate; they are different clocks. |
| Peer-review public-file check | 45 of 46 fresh US records checked; 32 ratings disclosed | For US firms, use enrollment as a baseline gate. A missing public rating is not a failed rating. |
| CPA licensing | No market percentage published | Verify the exact signing entity in the relevant state-board lookup before signing. |
Computed 2026-08-20. Missing and stale records are excluded, never entered as zero. Method, sample, provenance, and exclusions.
How do you choose a SOC 2 audit firm? Match the firm to the engagement, then verify that the signing entity is a licensed CPA firm. For a first Type 2 under 100 people, Zero Day CPA, Sage Audits, and Prescient Security have startup or growth-stage fit and listed fieldwork windows measured in weeks. For cloud-native SaaS heading into a multi-framework program, A-LIGN and BARR Advisory cover SOC 2 alongside ISO 27001 and other frameworks. For healthcare with HITRUST attached, shortlist LBMC and Coalfire. For federal and defense scope, start with Schellman and Fortreum. Pay a Big Four premium only when a customer contract, investor, or multi-jurisdiction engagement requires Deloitte, PwC, EY, or KPMG.
Quick Definition: A SOC 2 audit firm is a licensed CPA firm that examines your controls against the AICPA Trust Services Criteria and issues the signed attestation report. Under AICPA attestation standards AT-C 105 and AT-C 205, only a CPA firm can issue that opinion. Compliance platforms, readiness consultancies, and security testers can prepare you for the examination. None of them can sign it.
This guide uses the maintained auditor registry. The dated benchmark above applies a tighter freshness and verification floor than the full directory, labels price provenance, and keeps readiness-only providers out of the attestation sample.
Firm choice moves three things you care about: what you pay, when you get the report, and whether procurement accepts it without a fight. This page is the comparison method. If you already know what you want and just need names, start with the ranked shortlist. If you have your shortlist and need to run the process, use the auditor RFP walkthrough.
What is a SOC 2 audit firm, and who is legally allowed to sign the report?
Only a licensed CPA firm can issue a SOC 2 report. AT-C 105 and AT-C 205 place the examination inside the AICPA attestation framework, which restricts the opinion to CPA firms. Everyone else in the market prepares you for that examination: readiness consultancies, GRC platforms, penetration testers, and virtual CISOs all produce inputs, never the attestation.
The practical version: if a vendor offers to “certify” you, or promises a SOC 2 without naming the CPA entity that signs, you are talking to a preparer. That is not a problem in itself. Preparers do useful work, and many buyers hire one deliberately to keep the audit firm at arm’s length. It only becomes a problem when the preparer’s marketing lets you believe the report is coming from them. For where that line sits and when to hire each, see SOC 2 consultants vs auditors.
The wider category is worth knowing too, because the same firms show up under several names. Cybersecurity audit companies and IT audit companies overlap heavily with this list, and the distinction that matters is not what a firm calls itself but whether it can sign an AT-C 205 opinion.
Non-US firms complicate this cleanly rather than messily. The AICPA programme is a US construct, so a UK, EU, or Australian firm often runs the engagement while a named US CPA firm signs. That arrangement is legitimate, and the one fact to insist on is the name. A firm that delivers through a CPA partner but will not tell you which one has failed the only test that matters here.
Who can sign a SOC 2 report, and who only prepares you for one
| Provider type | Can sign the report | What you actually get | In our data |
|---|---|---|---|
| Licensed CPA firm | Yes | The examination and the signed AT-C 205 opinion | Auditor registry; verify the exact signing entity because current licence status is not normalized |
| Non-US firm delivering through a named US CPA partner | The named partner signs | Fieldwork locally, the opinion from the CPA of record | Named per firm, never generic |
| Readiness-only consultancy | No | Gap assessment, remediation plan, evidence prep | Listed separately from the attestation benchmark |
| GRC platform, penetration tester, or vCISO | No | Evidence automation, testing, programme management | Listed in our service-firm directory |
For the licensing rules themselves, see CPA licensing requirements for SOC 2 auditors and what a SOC 2 auditor is required to hold.
Which type of SOC 2 audit firm fits your company?
Three organization groups issue SOC 2 reports: assurance specialists, full-service CPA firms, and the Big Four. The group describes the firm’s commercial identity, not quality, capacity, or buyer fit. Use served-segment evidence, scope capability, licence and peer-review facts, timeline, and price for the actual decision.
If you are not yet sure whether the missing role is software, hands-on readiness help, or the report issuer, compare SOC 2 compliance provider roles first. This guide starts after that decision and focuses on selecting the independent audit firm.
Assurance specialists center their practice on SOC and information assurance
Assurance specialist is an organization identity, not a size rung: A-LIGN and a two-person practice can share the label. Their observed Type 2 estimates run from $2,500 to $150,000, so the group alone says little about price or capacity. Verify the exact frameworks, service market, proposed team, and report issuer for the engagement.
Full-service CPA firms carry SOC alongside broader accounting work
Full-service CPA firms are generalist accounting organizations: tax, audit, and advisory is the identity, while SOC is a practice line. The set includes BDO, RSM, and Grant Thornton as well as regional full-service shops. The median Type 2 planning band is $30,000–$80,000. The label does not prove multi-entity capacity or adjacent-framework coverage; confirm those facts in the proposal.
Big Four wins when a contract, an investor, or a five-jurisdiction footprint names it
Deloitte, PwC, EY, and KPMG become a hard requirement when the report recipient names a Big Four issuer. A global engagement may also make one network operationally useful, but that capability must be scoped rather than assumed from the label. The median Type 2 planning band is $60,000–$200,000.
Organization groups compared on price, timeline, and firmwide context
| Organization group | Firms | Median Type 2 band | Full observed range | Median fieldwork | Firmwide headcount |
|---|---|---|---|---|---|
| Big Four | 17 | $60K–$200K | $45,000–$450,000 | 6–18 wk | 6,000–140,000 |
| Full-service CPA | 94 | $30K–$80K | $15,000–$150,000 | 6–14 wk | 20–45,000 |
| Assurance specialist | 63 | $16K–$50K | $2,500–$150,000 | 4–10 wk | 2–2,000 |
Read the two price columns as two different statistics. The median band is what a typical engagement in that type gets quoted. The full observed range is the outer envelope across every firm in the type, and it is the column that should change how you shop: the types overlap so heavily that type alone barely predicts price. A full-service CPA firm’s floor of $15,000 sits below the specialist median floor. A specialist ceiling of $150,000 matches the full-service CPA ceiling. Only the Big Four floor of $45,000 clears most of the field, and full-service CPA ceilings still cross it. Fieldwork is the window from kickoff to report, not the whole engagement.
For the economics of the Big Four premium and how to negotiate it, see Big Four vs specialist SOC 2 auditors. That page owns the negotiation playbook; this one stops at which organization group to compare.
How much does each organization group cost in 2026?
A first SOC 2 Type 2 has a $16,000–$50,000 median band among assurance specialists, $30,000–$80,000 among full-service CPA firms, and $60,000–$200,000 among the Big Four. These are descriptive group aggregates, not capability or quality scores. Readiness work, extra Trust Services Criteria, and re-testing are separate lines.
What each line on a SOC 2 quote costs
| Line item | Typical range | What drives it |
|---|---|---|
| Readiness assessment | $10,000–$25,000 | Control maturity, whether a platform already holds your evidence |
| Type 1 examination | $10,000–$35,000 specialist, $40,000–$140,000 Big Four | Same scope work as Type 2 without the observation window |
| Type 2 examination, Security criterion | $16,000–$50,000 specialist, $60,000–$200,000 Big Four | System count, control count, subservice organizations |
| Each criterion beyond Security | $5,000–$12,000 | Availability and Confidentiality add testing, not scope debate |
| Privacy criterion | $8,000–$20,000 | Personal-data flows carry the heaviest evidence burden |
| Year two | Flat to a modest discount at specialists, commonly repriced upward at the Big Four | Whether first-year pricing was new-client investment |
Median Type 1 and Type 2 bands by organization group
| Organization group | Median Type 1 band | Median Type 2 band | What a Type 1 buys you |
|---|---|---|---|
| Big Four | $40,000–$140,000 | $60,000–$200,000 | A dated design opinion while a long observation window runs |
| Full-service CPA | $20,000–$60,000 | $30,000–$80,000 | A dated design opinion before the Type 2 observation period |
| Assurance specialist | $10,000–$35,000 | $16,000–$50,000 | A dated design opinion before the Type 2 observation period |
Now the part most directories leave out: most published price bands are planning estimates rather than firm-confirmed quotes. The dated benchmark above reports the current provenance split and excludes missing or stale records instead of turning them into zero. Treat every band here as a planning figure and get the scope and fee in writing before you budget against it.
Cost is a selection input here, not the topic. For the full model, see the SOC 2 audit cost guide, the Type 2 cost breakdown, and the startup pricing playbook.
How do you verify a SOC 2 audit firm is legitimate?
Four checks settle it: an active CPA licence in the licensing entity’s own name, enrolment in the AICPA peer review programme, a named signing partner who joins fieldwork, and a redacted prior report showing the AT-C 205 opinion and the tests-of-controls table. Run them in that order. The first two are public records and take about ten minutes.
The peer review check returns less than everyone promises
Every SOC 2 buying guide tells you to check AICPA peer review. We ran that check across the directory, and here is what it actually yields.
The dated benchmark above reports the fresh US peer-review denominator separately from pricing. It distinguishes records checked in the public file, enrollment among checked records, and disclosed ratings among checked records. A missing public-file result is not counted as “not enrolled,” and a missing rating is not treated as a failed rating.
Two conclusions follow. For a US CPA firm, enrolment is a baseline gate worth confirming. A disclosed rating is a weak discriminator on its own, and a missing rating is not a failed rating. Firms outside the US may not appear because the AICPA programme does not apply to them; other missing records may still be in our verification queue.
Check the licence in the entity name that appears on the engagement letter
State boards publish licence lookups. Search the exact legal entity named in your engagement letter, not the brand on the website. Groups that market under one name and sign under another are common and usually fine, but you want to see the licence attached to the entity that will sign your report.
Check who signs, and whether that person appears before the signature page
Ask for the signing partner by name, confirm they are a licensed CPA, and confirm they attend at least the scoping and closing meetings. “A partner will sign” is not an answer. On a well-run engagement you meet that person in week one.
Check a prior report, redacted
A firm that issues SOC 2 reports should be able to provide a redacted sample promptly. A glossy “certificate” or a badge image is not a SOC 2 report, and a firm that offers one instead of the real document has told you something. Verify first that the document is an actual report; then use it to see how the firm documents an engagement.
CPA licensure and peer-review enrolment are public baseline checks. They do not show whether the sample’s system description is specific or whether the testing is explained well enough for a report reader to follow. A redacted prior report cannot predict your engagement, but it provides a direct pre-engagement view of the firm’s report-writing and documented testing approach. The SOC 2 Quality Guild’s report-reliability rubric similarly treats a report as evidence to assess, rather than a verdict on whether a vendor meets a particular buyer’s needs.
| Inspect | Look for | Ask before you sign |
|---|---|---|
| Report structure | A coherent report with the opinion, management assertion, system description, stated scope, and testing results in a form you can follow. | Which parts will appear in our report, and who reviews the draft for completeness? |
| System description | Specific boundaries, services, and dependencies that make clear what was examined instead of broad marketing language. | How will you define our system boundary and describe material third parties? |
| Controls and criteria | Controls stated clearly enough to understand their purpose, with a visible connection to the relevant Trust Services Criteria. | Can we see how you map our controls to the criteria before fieldwork? |
| Test procedures | Procedures that say what was examined, the relevant population or period, and what result the auditor reached — not a repeated generic phrase. | How do you record population, selection, and evidence for the controls that matter most to us? |
| Internal consistency | Scope, dates, services, control descriptions, and testing results that agree across the report. | What report-level review catches contradictions before the report is issued? |
| Exceptions and opinion | Exceptions described where the tests are reported, with an opinion that does not leave their treatment unexplained. | When an exception occurs, how do you decide whether it changes the opinion or requires further work? |
These are discussion prompts, not a scorecard. A reports-per-CPA estimate, your impression of the firm’s leadership, or a claimed relationship with a GRC platform can prompt useful questions about staffing, review, and evidence exchange; none is a professional requirement or a verdict on audit quality. Using a GRC platform — or not using one — is not itself a quality concern. For annotated report passages, see our SOC 2 report example; for the separate authenticity check, see how to check a SOC 2 report is real.
Check independence before you bundle services
Independence is the reason the report has value. A firm that designs, implements, or tests a control and then forms an opinion on that same control creates a self-review threat under AICPA rules. Advisory work on what to fix is fine. Having your audit firm write your policies, build your controls, or run the security testing it will then evaluate is where the threat gets real, and a sceptical enterprise reviewer will ask. Get the separation described in the engagement letter.
The five checks, and what pass and fail look like
| Check | Where you run it | Pass looks like | Fail looks like | Our coverage |
|---|---|---|---|---|
| CPA licence | State board licence lookup | Active licence in the signing entity’s own name | Licence held by a different entity, or “affiliated with a CPA firm” | Not normalized in the registry; verify the exact signing entity before hiring |
| Peer review enrolment | AICPA peer review public file | Enrolled, review completed within three years | Not enrolled, or enrolment lapsed | Fresh checked and enrolled denominators are reported in the benchmark above |
| Peer review rating | Same file | The exact published result: Pass, Pass with Deficiencies, or Fail | No rating published (not a Fail), or a result the firm cannot explain | Disclosed-result breakdown is on the data page; we do not treat non-disclosure as failure |
| Signing partner | Engagement letter and kickoff call | A named CPA who joins fieldwork | ”A partner will sign” with no name | Not published per firm; ask directly |
| Prior report | Ask for a redacted sample | AT-C 205 opinion plus a tests-of-controls table | A certificate, a badge, or a summary letter | Report format is a standing question in our firm reviews |
| Independence | Engagement letter | The firm does not audit controls it built or tested | Same firm sells remediation, then opines on it | Flagged in review when a firm bundles both |
Deeper reading on the credential layer: AICPA membership verification, what peer review does and does not prove, state CPA licensing rules, and, once you hold a report, how to check a SOC 2 report is real.
What should you ask a SOC 2 audit firm before you hire them?
Eight questions separate firms fast: SOC 2 volume in your industry, cloud environments the team works in daily, who runs your engagement day to day, whether the signing partner joins fieldwork, how evidence is collected, what happens when a control fails testing, what re-testing costs, and what year two costs. Vague answers to any of them are the finding.
The discovery call is where a firm’s real capability shows, and it costs you an hour. Ask for specifics and listen for whether the answer contains a number, a name, or a scenario. Generalities are the tell.
Eight questions, and how to read the answer
| Question | A strong answer | A weak answer |
|---|---|---|
| How many SOC 2 examinations did you complete last year, and how many in our industry? | A number, plus two or three anonymized scenarios | ”We work with lots of tech companies” |
| Which cloud environments does the team work in weekly? | Named services and how they sample them | ”We are cloud agnostic” |
| Who runs the engagement day to day, and what is their level? | A named senior with their SOC 2 history | ”You will be assigned a team” |
| Does the signing partner attend fieldwork or only sign? | Scoping, mid-point, and closing at minimum | ”The partner reviews at the end” |
| How is evidence collected and tracked? | A portal, or a documented request list with owners | Email threads and shared spreadsheets |
| What happens when a control fails testing? | A described path: remediate, re-test, or note the exception | ”That rarely happens” |
| What do re-testing and scope changes cost? | Named rates or a fixed re-test fee in the statement of work | Silence, or “we handle that case by case” |
| What is year two, and what changes? | A number and the reason it moves | ”We will look at it next year” |
Ask two or three recent references in your industry the one question that matters: what went wrong, and how did the firm handle it. A reference that only describes a smooth engagement tells you nothing about the firm under pressure.
How do you compare SOC 2 audit proposals side by side?
Two SOC 2 proposals are only comparable when both price the same seven lines: scope, observation window, fieldwork dates, deliverable and draft date, re-testing, readiness work, and year two. Most quote spread across firms is not a price difference, it is a scope difference that nobody itemized.
The seven lines every proposal should price
| Line | Require in writing | Where quotes diverge |
|---|---|---|
| Scope | Systems, entities, and which Trust Services Criteria | One firm quotes Security, another quotes three criteria |
| Observation window | Start and end dates in months | A 3-month window quoted against a 12-month window |
| Fieldwork | Kickoff date and expected duration | ”Q3” versus a dated schedule |
| Deliverable | Draft date, final date, and format | Draft dates that slip into your renewal cycle |
| Re-testing | Fixed fee or hourly rate, stated up front | The most common surprise invoice |
| Readiness and gap work | Included, optional, or excluded | Bundled by one firm, billed separately by another |
| Year two | A number or a stated method | Left blank, then repriced after you are committed |
Why we make every firm price the same lines
When we take a buyer’s scope to firms, we ask each of them to price those seven lines and nothing else changes between the briefs. It is the only way three quotes become three comparable numbers rather than three different offers. Do the same thing yourself: write the seven lines once, send the identical text to every firm, and refuse to normalize their formats afterwards. If you would rather not run that loop, our quote comparison service does it, and the RFP walkthrough covers the process end to end with a weighted decision matrix.
One warning on the cheapest bid: price only a normalized written scope. A later rejection may concern the issuer, but it may instead concern licence or peer review, independence, scope, period, opinion, exceptions, or the reporting entity. Ask the recipient what it requires rather than translating every objection into brand familiarity.
Which SOC 2 audit firm fits your company profile?
Fit beats organization identity. A 30-person AI startup and a 3,000-person healthcare platform need different scope, capacity, and recipient-reliance facts even at the same budget. Below, 14 firms map to specific buyer profiles and link to their full records.
First SOC 2, small team, price is the constraint
Under about 100 people with a single product, compare the complete fee, fieldwork window, and evidence workflow. Chiaro works with 1-20 person teams and holds the lowest confirmed price in our data. Zero Day CPA targets first-time startup audits, while Sage Audits offers partner-led work and commonly includes readiness with a Type 1 engagement. More at SOC 2 auditors for startups.
Cloud-native SaaS heading into a multi-framework program
If ISO 27001, HIPAA, or PCI is coming after SOC 2, buy the bench now. A-LIGN and BARR Advisory run multi-framework programs as a normal engagement shape rather than a special case, and Prescient Security and Sensiba LLP both work natively with the major GRC platforms. More at SOC 2 auditors for SaaS.
Healthcare, fintech, and other regulated scope
Regulated scope is where an adjacent accreditation earns its keep. LBMC pairs SOC 2 with HITRUST for healthcare; Coalfire covers SOC 2 alongside PCI DSS and FedRAMP for payments and cloud infrastructure. More at SOC 2 auditors for healthcare and SOC 2 auditors for fintech, and, if HIPAA is riding along, how a SOC 2 plus HIPAA overlay engagement is structured.
Federal, defense, and public-sector scope
If FedRAMP or CMMC sits next to your SOC 2, choose a firm that holds those authorizations, because the evidence overlaps heavily. Schellman and Fortreum both do. More at FedRAMP 3PAO firms that also issue SOC 2.
Enterprise, multi-entity, or outside the United States
Multi-entity and multi-jurisdiction scope requires direct evidence about the engagement team, issuing entity, and area served. In the UK and EU, Tempo Audits delivers through a named US CPA partner, while Grant Thornton UK issues through its own practice. More at SOC 2 auditors for enterprise and SOC 2 auditors in the UK.
Firm fit by buyer profile
| Your profile | Firms that fit | Why they fit | Type 2 band |
|---|---|---|---|
| 1-20 people, first report, AI-native or solo-founder | Chiaro | Built for the smallest scope, price confirmed by the firm | $2,500–$6,670 |
| Under 100, first Type 2, short listed fieldwork window | Zero Day CPA, Sage Audits | Startup-focused practices with 2–7 week directory ranges | $7,000–$20,000 |
| Series A to C SaaS already on Drata, Vanta, or Secureframe | Prescient Security, Sensiba LLP | Platform-native evidence intake, VC-backed client base | $10,000–$50,000 |
| Multi-framework program: SOC 2 plus ISO 27001 and more | A-LIGN, BARR Advisory | Multi-framework is their default engagement, not an exception | $15,000–$50,000 |
| Mid-market without an enterprise budget | KirkpatrickPrice | Named practice, mid-market pricing, long SOC 2 history | $12,000–$45,000 |
| Healthcare with HITRUST or a payments overlay | LBMC, Coalfire | HITRUST and PCI DSS accreditation alongside SOC 2 | $20,000–$120,000 |
| Federal, defense, FedRAMP, or CMMC scope | Schellman, Fortreum | FedRAMP 3PAO authorization, government-scope experience | $20,000–$100,000 |
| UK or EU entity | Tempo Audits, Grant Thornton UK | Local delivery, with the CPA of record named on the report | $10,000–$120,000 |
Bands are the Type 2 range we hold for the named firms. Except where a firm has confirmed its number, they are our estimates. To filter the whole set yourself, use the auditor directory; to see the firms we rate highest by use case, see the ranked shortlist.
Does your SOC 2 auditor need to know your GRC platform?
It helps and it is not a requirement. Auditor familiarity with your platform shortens evidence review, because the firm already knows what a Vanta or Drata export looks like and what it omits. The counts in our directory are not what most buyers expect: Sprinto is named by 44 firms, Drata by 48, Vanta by 38, and Secureframe by 12.
Which platforms SOC 2 firms name in our directory
| Platform | Firms naming it | What that means for you |
|---|---|---|
| Sprinto | 44 | Broad support, including many full-service CPA firms |
| Drata | 48 | The widest named auditor support in our data |
| Vanta | 38 | Broad support across specialist and larger firms |
| Secureframe | 12 | Concentrated among specialists |
| No platform named | 108 | The majority still run evidence through their own process |
Read that table carefully, because it is easy to misread. It counts what firms tell us they support, not platform market share and not audits performed. Vanta is the larger platform by installed base; it is simply named by fewer firms in our directory than Sprinto is. The useful conclusion is narrower and more practical: whichever platform you run, ask the firm directly whether it has taken evidence out of that platform before, and what it asked for on top. The gap between “we integrate” and “we have done this” is where fieldwork time goes.
Also worth knowing: 108 of the 174 firms name no platform at all. That is not a red flag, it is the market. A firm with a documented evidence request list and a portal of its own can run a clean engagement without ever logging into yours. For the platform side of this decision, see SOC 2 compliance software, or filter directly to auditors who work with Vanta, Drata, Secureframe, or Sprinto.
Does the firm need your industry or an adjacent accreditation?
Industry experience is a scoping shortcut, not a requirement: a firm that has audited your vertical needs fewer walkthroughs to understand your control environment. An adjacent accreditation is different. If HITRUST, PCI DSS, FedRAMP, or ISO 27001 is coming, a firm that holds it can reuse evidence across both engagements.
Industry experience buys you speed, not a better opinion
The opinion is the same document regardless of who signs it. What vertical experience buys is fewer explanatory calls, better-targeted evidence requests, and an auditor who does not treat a normal pattern in your industry as an anomaly. It matters most where the control environment is unusual: healthcare data flows, payment environments, multi-tenant infrastructure, and anything touching government.
Credentials firms hold alongside SOC 2
| Credential | Firms holding it | When it matters to you |
|---|---|---|
| AICPA member firm | 155 | Baseline for any firm signing an attestation report |
| PCI DSS QSA | 28 | You process card data and want one firm across both |
| PCAOB registered | 21 | Your customers or investors are public companies |
| HITRUST assessor | 24 | Healthcare buyers ask for HITRUST alongside SOC 2 |
| ISO 27001 certification body | 20 | You need certification, not just a readiness opinion |
| ISO 42001 | 12 | You ship AI features and enterprise buyers have started asking |
| FedRAMP 3PAO | 11 | You sell to federal agencies or their prime contractors |
Counts reflect what each firm publishes about itself in our directory, checked at review time rather than continuously. Confirm any credential that will affect your engagement directly with the issuing body. If you need two frameworks at once, the SOC 2 and ISO 27001, HITRUST, and PCI DSS QSA listings filter the directory to firms that hold both.
What are the red flags that should end the conversation?
Six red flags are worth walking away over: a quote with no itemized scope, no confirmable peer review enrolment, an unnamed signing partner, evidence collection by email, pressure to sign before you have read the statement of work, and no reference from your industry. Any one of them predicts a difficult engagement.
Six red flags and what to do instead
| Red flag | Why it matters | What to do instead |
|---|---|---|
| Vague pricing with no itemized scope | Every unpriced line becomes a change order later | Require the seven proposal lines in writing before you compare |
| Peer review enrolment cannot be confirmed | A firm issuing attestation reports outside the programme is a hard stop | Look it up yourself in the public file, then ask the firm to explain any gap |
| No named signing partner before contract | The person accountable for the opinion is unidentified | Ask for the name and confirm they attend scoping and closing |
| Evidence collected by email and spreadsheet | Your team spends weeks on request management instead of remediation | Ask to see the portal or the documented request list before signing |
| Pressure to sign before you have read the statement of work | The rush is the tell; scope disputes surface after signature | Take the week. A firm that cannot wait a week cannot run a six-month engagement |
| No reference from your industry or company size | The firm has not done your engagement before | Ask for two references and ask each what went wrong |
A softer flag worth naming: a firm that offers to remediate your controls and then audit them. It is not automatically disqualifying, but it puts the firm’s independence in play, and a careful enterprise reviewer will notice. Ask how the two engagements are separated, in writing, before you bundle.
How long does the whole engagement take?
A first SOC 2 Type 2 runs six to twelve months end to end, and the observation window is most of it. Fieldwork, the part your auditor controls, runs 4-10 weeks at specialists and regional firms and 6-18 weeks at the Big Four. Firm choice moves the fieldwork phase and the report turnaround. It cannot shorten the observation period.
The five phases of a first SOC 2 engagement
| Phase | Typical duration | Who owns it | Most common delay |
|---|---|---|---|
| Readiness assessment | 2–6 weeks | Auditor or a separate readiness firm | Waiting on system access to start |
| Remediation | 1–6 months | You | Controls that need a tool purchase, not a policy |
| Observation window | 3–12 months, 6 typical for a first report | You, with the clock running | Discovering a control gap late in the window |
| Fieldwork | 4–18 weeks depending on scope and firm | Auditor | Evidence arriving in the wrong format |
| Report and management review | 2–4 weeks | Auditor, then you | Management assertion sitting unsigned |
The delays that actually hurt are late gap discovery and disorganized evidence, and a readiness assessment is the cheapest insurance against both. If your deadline is a customer contract, work backwards from the report date and treat the observation window as fixed. For the full timeline model, see how long a SOC 2 audit takes and the audit team composition guide.
How we verify and rank the firms in this guide
We are an independent directory, not an audit firm and not a reseller. Every firm record starts from public sources: the firm’s own materials, state CPA licence lookups, the AICPA peer review public file, and, where the firm engages with us, direct confirmation. The dated benchmark above publishes the current eligibility, verification, peer-review, and pricing-provenance denominators. Estimated prices remain marked as estimates.
Fit decides whether a firm belongs in a list and what we say about it. A paid placement receives a Sponsored label and additional visibility, but payment cannot make an ineligible firm qualify or change our fit assessment. Firms that only prepare clients for an audit are excluded from auditor listings entirely, because they cannot sign the report. Full detail, including what each verification stamp asserts and how we make money, is on our methodology page.
Common questions about choosing a SOC 2 audit firm
Can any CPA firm issue a SOC 2 report?
Legally yes, practically the firm still needs the competence, independence, and resources to perform the engagement. AT-C 105 and AT-C 205 require a licensed CPA firm. Ask how many SOC 2 examinations the proposed team completed in the last twelve months, how many matched your scope, and who will perform and review the work. Treat an unanswered volume question as missing evidence, not a brand verdict.
How do you know if a SOC 2 audit firm is reputable?
Run four checks: an active CPA licence with the state board, in the signing entity’s own name; enrolment in the AICPA peer review public file; a named signing partner who joins fieldwork; and a redacted prior report showing the AT-C 205 opinion and the tests-of-controls table. Expect the peer-review lookup to be less decisive than its reputation suggests: some checked records do not disclose a rating, which is not the same as a failed rating.
What accounting firms provide SOC 2 audits?
Three organization groups: the Big Four (Deloitte, PwC, EY, KPMG); full-service CPA firms, from BDO and RSM through regional shops; and assurance specialists such as A-LIGN, Schellman, BARR Advisory, KirkpatrickPrice, and Prescient Security. The group is a browsing aid, not a quality or fit verdict.
What is the difference in quality between regional and national SOC 2 audit firms?
The opinion follows the same professional standard, so quality does not track letterhead. We classify both as full-service CPA firms when tax, audit, and advisory form the organization identity and SOC is a practice line. Assurance specialists are SOC or information-assurance first. In our directory the assurance-specialist median Type 2 band is $16,000–$50,000 against $30,000–$80,000 for full-service CPA firms. Neither group is inherently more rigorous.
Does the auditor’s brand name matter to enterprise customers?
Less than many buyers assume, but only the relying party can answer. Procurement teams read the scope, criteria tested, exceptions, opinion, period, entity, licensing, peer-review evidence, and independence. Ask whether the recipient requires a named firm, Big Four issuer, recognized security-assurance practice, or preapproval. Without a stated requirement, do not promise acceptance from the organization label.
Can you switch SOC 2 audit firms after the first year?
Yes, and it is routine. Independence rules do not lock you in. Give the incoming firm your prior report and the underlying evidence; it runs its own risk assessment and starts a fresh observation period rather than repeating your first year. Budget two to four extra weeks at the start for the handover, and switch between report periods rather than mid-window.
Should the same firm do your readiness work and your audit?
It is allowed and common, but keep the line visible. A firm that designs or operates a control and then opines on that same control creates a self-review threat under AICPA independence rules. Gap assessment and advice on what to fix are fine. Having the audit firm write your policies, build your controls, or run the security testing it will then evaluate is where independence gets thin. Ask the firm to describe the separation in the engagement letter.
Is a “pass with deficiency” peer review rating disqualifying?
No, but it earns a question. Peer review covers a firm’s whole accounting and auditing practice, so a deficiency may sit nowhere near its SOC practice. Ask which engagements the finding touched and what changed afterwards. The disclosed-result breakdown is published from the current snapshot on the AICPA peer-review data page; a missing public result is not a Fail, and a firm carrying a non-Pass should be able to explain the finding in detail.
What is the difference between a readiness assessment and the audit?
A readiness assessment is consultative. Someone compares your current controls to the Trust Services Criteria and hands you a remediation list. It produces no attestation and nothing a customer can rely on. The audit is a formal examination by a licensed CPA firm that results in the signed report. Readiness is optional, the AICPA does not require it, and it is the cheapest protection against discovering a gap in month five of a six-month observation window.
You have the method. The three next steps, in the order most buyers take them: see the firms we rate highest by use case on the ranked shortlist, filter the full set by organization group, price, country, and vertical in the auditor directory, and when you are ready for numbers, request quotes so firms price your scope instead of you chasing five of them. Your identity stays private until you pick who to talk to.