Client Accounting Services (CAS), Explained: What It Is and What the Benchmark Shows

Client accounting services, shortened almost everywhere to CAS, is the name a firm gives to running a client’s accounting on an ongoing basis instead of touching it once a year at tax time. CPA.com, which publishes the only free public benchmark of these practices, describes CAS as a spectrum rather than a single service: it runs from financial CAS, meaning transactional bookkeeping up through controller work, to business insights CAS, meaning higher-level advisory built on financial and non-financial information. In the 2024 CPA.com and AICPA PCPS CAS Benchmark Survey, a self-selected sample of 206 firms, the median practice reported $1,606,409 of annual net client fees, 17 percent growth over the prior year and a 50 percent margin before partner salaries or draws.

The short version: CAS is recurring accounting work sold for a fixed monthly fee rather than by the hour, and in the 2024 benchmark only 10 percent of respondents still billed hourly, against 53 percent in the 2018 edition.

What CPA.com means by client accounting services

CPA.com publishes no one-line dictionary definition. What it publishes is a spectrum, and the distinction it draws inside that spectrum is the useful part. In the foreword to the 2024 report, Kimberly Blascoe, CPA, Senior Director of CAS Professional Services at CPA.com, describes firms struggling “to successfully make the often-complicated transition from financial CAS (transactional to controller services) to business insights CAS (higher-level advisory services based on financial and non-financial insights).”

The survey also defines the deepest version of the service. In its own words, the 2024 survey defined outsourced accounting as “services for clients where the CAS practice serves as primary accounting or finance staff (e.g., your firm has replaced the majority of the accounting department and accounting function for the client).”

So three things sit under one acronym: transactional accounting, controller-level work, and advisory. Where the firm replaces the client’s accounting department outright, CPA.com calls that outsourced accounting. CPA.com also sells a branded framework for building such a practice, CAS 2.0, which is its own product rather than a profession-wide standard.

Financial CAS: transactional through controller

At the transactional end the deliverable is the cycle: transactions coded, bank and card accounts reconciled, payables and receivables run, a month-end close performed and statements issued. Our month-end close checklist sets out that cycle step by step. Controller-level work adds review rather than volume: someone owns the chart of accounts, approves journal entries, checks the subledgers against the control accounts and signs the period off.

Business insights CAS

This is the advisory end Blascoe describes, built on top of books the firm already controls. It is not attest work and it requires no license of any kind. Where the client needs forecasting, budgeting and a board-grade reporting pack rather than compliance, the honest description of that hire is fractional CFO work, and what a fractional CFO costs covers what that is priced at.

Outsourced accounting

The firm becomes the accounting department. That is a different risk profile from bookkeeping, because the client has no internal check on the work, and it is the version of CAS most likely to need a written scope, a named reviewer and an engagement letter that says what happens when the scope moves.

What the benchmark survey is, and what it is not

Every figure on this page comes from one survey, and its limits belong next to its numbers.

The 2024 CPA.com and AICPA PCPS Client Advisory Services Benchmark Survey opened for participation on May 1 and closed after 13 weeks. In the report’s words, it was marketed “to previous respondents, to firms and practices that opted in to receive information about CAS from the AICPA and CPA.com, and broadly through advertising and social media targeting the accounting profession.” The result: “206 respondents self-selected to participate in the survey,” and “of the 206 responses, most questions received between 161 and 190 responses, with a mode of 181.”

Two more things the report says about itself. It acknowledges the obvious bias: “While some statistical self-selection bias is expected, we believe that based on respondents’ varying sizes and service offerings, these respondents are a sufficiently representative sample.” And every figure it publishes is a median, chosen deliberately: “we again chose to report the median values of the respondent data to represent the middle value, rather than reporting means (averages) which may be skewed by very large or very small practices.”

Read it as association and vendor research. CPA.com sells CAS coaching, consulting and the CAS 2.0 framework that the survey’s recommendations point toward. That does not make the numbers wrong; it means they describe firms that opted into a CAS survey run by a body selling CAS services, not the profession. The 2024 edition is the current one as of September 2026, and the next edition is due in December 2026.

The numbers the 2024 survey reports

All medians. All from the 2024 edition, 206 self-selected respondents, most questions answered by 161 to 190 of them.

Three definitions have to travel with that table, or it will be misread.

“Top performers” is a revenue-per-head quartile, not a quality ranking. The report classifies them “using the top quartile based on net client fees per professional (NCFPP),” and warns in its own text that “NCFPP is not without limitations and may not accurately reflect other metrics that serve as indicators of successful practices such as growth, average revenue per client, or total annual reportable CAS revenue.” They also skew large: firms earning over $5 million in revenue made up 46 percent of the respondent pool but 71 percent of the top performers.

NCFPP is revenue divided by heads. The report calculates it “by dividing the total annual reportable CAS revenue (net of write-offs) by the total number of full-time equivalent staff (FTE), including outsourced and offshored staff.” Offshored and outsourced staff count, which matters when comparing a firm that offshores against one that does not.

The 50 percent margin is not a profit margin. The 2024 question was changed to margin “before partner salaries or draws,” defined as “CAS gross revenue less direct staff costs, divided by CAS revenue.” Partner compensation, rent, software, insurance and every other overhead sit below that line. The report itself says comparison between firms “may be difficult due to the varying methods of calculating these inputs” and that margins “work best as an internal metric.”

The movement over four editions is the more durable finding, since each edition is a different self-selected group:

Between the 2022 and 2024 editions the report records median reportable annual CAS revenue rising by 61 percent, median net client revenue rising 30 percent while median total CAS employee FTE rose 31 percent, and NCFPP rising 29 percent to $156,250. Revenue and headcount moved almost together, which is the number to sit with if the pitch you have heard is that CAS scales without staff.

For a profession-wide comparison the same report cites the AICPA’s 2023 National Management of an Accounting Practice survey, which “reported a median increase in firm net clients fees of 9.11% over the previous year.” CPA.com’s own positioning claim, from CEO Erik Asgeirsson in the foreword, is that CAS “is now the fastest growing service area for the profession.” That is the publisher’s claim, supported inside the report by its own self-selected survey set against that MAP figure.

How client accounting services are priced

This is the finding with the clearest trend behind it. The report’s insight #7 is headed “Pricing in CAS has shifted away from pure time and materials billing,” and the chart of respondents relying on hourly billing runs 53 percent in 2018, 27 percent in 2020, 25 percent in 2022 and 10 percent in 2024.

On what replaced it, verbatim: “Value billing is still rare, but 84% of all respondents are shifting to fixed-fee billing that’s payable on a monthly, quarterly or annual basis.” The report adds that “in spite of the trend toward fixed-fee pricing, many firms report billing in arrears rather than up-front pricing,” and that many respondents do not charge separately for common services: only 32 percent of all respondents, and 30 percent of top performers, charge a separate fee for an initial CAS client assessment.

Two fee figures are published, both medians:

The report notes the written-plan cohort’s monthly fee is “$1,000 higher than the median of all respondents and $350 per month higher than the top performers.”

A $3,000 median monthly fee describes a substantial engagement, not a bookkeeping subscription. For the other end of the market, Ignition’s 2025 U.S. Accounting and Tax Pricing Benchmark, an online survey of 219 of its own US accounting-firm customers fielded in July 2025, reports the share of firms in each monthly band for bookkeeping and accounting: 4.3 percent under $250, 29 percent at $250 to $499, 27.1 percent at $500 to $749, 16.7 percent at $750 to $999, 12.9 percent at $1,000 to $1,499, 6.7 percent at $1,500 to $2,500 and 3.3 percent over $2,500. Ignition sells proposal and billing software and states that its sample consists of its own customers, “a group that tends to have more structured pricing processes and tools in place,” so it is not representative either. What it does show is a distribution that sits well below the CAS median, which is consistent with the two surveys describing different work.

If you are a business owner comparing a firm’s CAS proposal against a national online provider, what bookkeeping services cost sets out the published entry prices at the national providers, which run from $99 to $399 a month as of September 2026, and what each of those plans leaves out.

The niche finding, and why it is the only defensible growth claim here

The same survey reports separately on firms drawing more than 50 percent of CAS revenue from defined industry niches. For that group, verbatim: “Only 12% bill only on time and materials,” “Median CAS revenue is over $2.2 million,” “More than 65% report that all or most of the referrals that they receive are aligned to their ideal client profile,” and “Median revenue growth over the previous year was 19%.” The report also records that 29 percent of respondents are not yet serving defined client industry niches.

That is a correlation inside a self-selected sample, not proof that picking a niche causes growth. It is still the only growth claim on this subject that carries a named survey, a year and a sample, which is more than the usual advice about winning clients has behind it. How to get accounting clients works through what else is and is not measured.

The software a CAS practice runs on

Two layers, and firms routinely confuse them when budgeting.

The ledger is the client’s accounting system, and the firm usually works inside whatever the client has. Accounting software covers the options by business type and size.

The practice layer is the firm’s own system: workflow, client records, documents, proposals, engagement letters, billing, and close tracking across a book of clients. Accounting practice management software compares eleven products and every price each one publishes. The thing to notice when modeling a CAS practice is that the products are priced on two different units, per user and per client, and the arithmetic diverges fast. A plainly hypothetical example, using list prices published in September 2026: a firm with 6 staff and 40 clients pays $534 a month for 6 seats of Karbon Business at $89 per user per month billed annually, while Double, priced per connected client at $10, $25 or $50 a month, costs the same firm $400 to $2,000 a month for the same 40 clients no matter how many staff it has. Per-seat pricing punishes headcount; per-client pricing punishes small clients.

Close-specific tooling is priced the same way. Financial Cents sells a Month-End Close add-on at $5 per client per month billed annually, on top of its per-user plans.

Should a firm build a CAS line?

The survey gives four things worth weighing and does not answer the question.

• The margin figure is before partner draws. A 50 percent median margin on that definition is not the margin the firm keeps. Model your own number with partner time in it before deciding the line is profitable.
• Revenue and headcount grew almost in step between the 2022 and 2024 editions, 30 percent against 31 percent. Treat “CAS scales” as a claim to test on your own capacity plan.
• Fixed fee means scope discipline or nothing. With 84 percent of respondents moving to fixed fees, and only 32 percent charging a separate fee for an initial CAS client assessment, the work of establishing what a client’s books actually look like is being absorbed by most respondents rather than billed.
• The benchmark firms are large. A median CAS practice of $1.6 million in net client fees is not a solo practitioner’s second service line. If you are starting from zero, how to start a bookkeeping business is the nearer question.

If you are a business owner and CAS has appeared on a proposal, ask four things: what is inside the fixed fee and what is out of scope, whether out-of-scope work is monitored and billed or absorbed, who does the work and who reviews it, and whether the tax return is included. The last one catches people out regularly, because bookkeeping and tax compliance are priced separately at most firms.

Who to bring in, and when

A CAS engagement is not attest work, so no credential is required for any part of it, and a bookkeeper, an enrolled agent, a CPA firm or an outsourced provider can all deliver it. The credential starts to matter at the edges: if a lender or investor asks for a compilation, a review or an audit, that report has to come from a licensed CPA firm, and the firm keeping your books is not automatically able to issue it. Ask early whether your provider can, or who they would refer it to. Our directory lists CPA firms by state and city, and where the gap is forecasting and a reporting pack rather than a monthly close, fractional CFO work is the better description of the hire. Nothing here is tax or legal advice; take your own situation to your own adviser.

Frequently Asked Questions

Sources

8 links

• CPA.com and AICPA PCPS, 2024 CAS Benchmark Survey, full report (PDF)
• CPA.com, CAS Benchmark Survey landing page
• CPA.com and AICPA PCPS, 2022 CAS Benchmark Survey (PDF)
• CPA.com and AICPA PCPS, 2018 CAS Benchmark Survey executive summary (PDF)
• Ignition, 2025 U.S. Accounting and Tax Pricing Benchmark
• Karbon pricing
• Double pricing
• Financial Cents pricing