Client accounting services (CAS) are an outsourced arrangement where a CPA firm runs some or all of your finance function, from bookkeeping and the monthly close to controller oversight and CFO-level strategy, for a predictable fee.
Learn about what CAS includes, what it costs, and how to choose a partner.
What Are Client Accounting Services (CAS)?
CAS vs. CAAS vs. Outsourced Accounting vs. BPO: What the Terms Mean
Term | What it usually means |
Client Accounting Services (CAS) | Ongoing outsourced accounting, from transactions to reporting |
Client Advisory Services / CAAS | CAS plus forecasting, planning, and decision support |
Outsourced accounting | Handing off all or part of the accounting function |
Business process outsourcing (BPO) | Outsourcing recurring transaction work: AP, AR, reconciliations, payroll entries |
How CAS Differs From Traditional Bookkeeping
Bookkeeping records what happened. CAS adds the close, financial statements, controls, and senior review of whether the numbers make sense.
What’s Included in Client Accounting Services
At Windes, services build on each other: controller and CFO support include our Advanced outsourced accounting, and FP&A can be added on top.
Bookkeeping and Transactional Accounting
This covers bank and credit card reconciliations, payroll journals, 1099 filings, and fixed asset schedules. Our Basic tier is cash basis; Advanced supports cash or accrual and adds AR invoicing, accrual adjustments, and automated accounts payable.
Fractional Controller Services
A fractional controller adds oversight: custom reporting, process improvements, audit support, internal controls, consolidated financials, board reporting, and covenant compliance.
Fractional CFO Services
A fractional CFO brings budgeting, forecasting, scenario planning, bank relationships, capital raising, M&A due diligence, and board advisory.
Business Insights and FP&A
FP&A turns a reliable close into insight on past performance, where you stand today, and what’s next.
Add-On Services
Historical cleanup, sales tax, payroll processing, and California filings such as Form 571-L and the Statement of Information.
Operations First, Oversight Second: Why the Order Matters
Put a fractional CFO on top of books that can’t close reliably, and you get an expensive person waiting for data. Outsource processing with no oversight, and you get clean books nobody interprets. Fix the close first, then add judgment.
Benefits of Client Accounting Services
Specialized Expertise Without Hiring for Every Role
You get staff accountants, controllers, and CFO-level advisors instead of one hire expected to do everything.
Continuity and Stronger Internal Controls
If one bookkeeper’s absence would stop payments, that’s a control weakness, not an inconvenience. A team provides coverage and segregation of duties.
Capacity That Scales in Smaller Increments
Many growing companies need roughly 60% of a controller and one and a half accountants. Hiring whole people overshoots one way and underserves the other.
Faster, More Reliable Financial Visibility
A consistent close date means timely statements, clearer cash flow, and confident answers when lenders or investors ask.
How Much Do Client Accounting Services Cost?
There’s no universal price list, and any quote given before seeing your books is a guess.
What Drives CAS Pricing
Transaction volume, number of entities, cash vs. accrual basis, reporting frequency, the level of strategic support, and the condition of your books.
Common CAS Pricing Models
Expect a fixed monthly fee for ongoing work, value-based pricing for advisory, and hourly fees for cleanup projects. Ask what triggers extra charges and whether software subscriptions are billed separately.
Comparing CAS to the Fully Loaded Cost of an In-House Team
Don’t compare a fee to a salary. Add benefits, payroll taxes, software, recruiting, turnover coverage, and the cost of a bad hire. Then weigh continuity and access to specialists you need only occasionally.
CAS vs. In-House Accounting vs. a Solo Bookkeeper
| CAS team | In-house department | Solo bookkeeper |
Depth of expertise | Bookkeeping through CFO | Limited to who you hire | Usually transactional |
Continuity | Built-in coverage | Exposed to turnover | Single point of failure |
Scalability | Adjusts by scope | Requires hiring | Capped by one person |
Cost structure | Predictable fee | High fixed cost | Low cost, coverage gaps |
Control | Shared, with defined reporting | Full | Full, little oversight |
Our view: firm size matters less than depth across disciplines plus direct access to experienced partners. Windes pairs large-firm technical depth with a partner-led team you can actually reach.
Technology and AI in Modern Client Accounting Services
Cloud Accounting Platforms
Windes is a Sage Intacct Accountants Program (SIAP) Partner, so you and your CAS team share the same real-time view.
What Automation Handles and What Still Needs Human Judgment
Automation handles data entry, transaction matching, and AP workflows. It can’t tell you whether a margin trend is a warning sign or a covenant is at risk. That still takes experienced people.
Data Security and Who Owns Your Financial Data
You should own your systems and data. Ask how access is controlled and what happens to your data if you switch providers.
How CAS Connects to Tax, Audit, and Advisory
The Advantage of One Firm Across Disciplines
With tax and advisory professionals in the same firm, planning opportunities surface during the year instead of at filing time.
Why Auditor Independence Matters When One Firm Does Both
If a firm audits your financial statements, independence rules limit the accounting work it can also do for you. A reputable firm explains upfront how it handles this.
Signs Your Business Is Ready for CAS
- Your close lands on a different day every month
- Transaction volume is outgrowing your team
- One person holds the entire process
- Capable staff spend their days processing, not analyzing
- A first audit, lender, or investor is raising the bar
For a deeper look, read When Should a Growing Business Outsource Accounting Operations?
What CAS Won’t Fix, and What Your Team Still Owns
Your CAS team inherits your chart of accounts and workflows, so structural problems come along. That’s why cleanup belongs in onboarding. You’ll still need an internal owner to approve payments and make decisions.
What to Expect During CAS Onboarding
- Assessment: We review your systems, processes, and books.
- Cleanup and setup: We fix the chart of accounts and workflows.
- First close: Expect it to be slower than today, not faster.
- Steady state: A documented close calendar and reporting cadence.
Most transitions take one to three close cycles.
How to Choose a Client Accounting Services Provider
Questions to Ask Before You Sign
- What exactly is in scope, and what costs extra?
- Who owns the close calendar?
- What are your turnaround commitments?
- What happens when our volume spikes?
- Who will actually do the work?
- Which platforms do you support?
Red Flags to Watch For
Quotes given without reviewing your books, vague scope, no named team, promises of a faster first close, and no clear answer on data ownership or independence.
Client Results: CAS in Practice
Creative Agency Cuts Its Month-End Close by 60%
A creative agency had outgrown its accounting processes. Windes helped it implement Sage Intacct to streamline its financial operations. The result: a 50% reduction in administrative burden and a month-end close 60% shorter.
Client Accounting Services at Windes: 100 Years of Client Relationships
Since 1926, Windes has grown from a small Long Beach practice into a firm of more than 250 professionals.
Industries We Serve
Construction, manufacturing, real estate, wholesale and distribution, technology, professional services, medical practices, nonprofits, and more.
Serving Long Beach, Los Angeles, Orange County, and Clients Nationwide
Our CAS team provides onsite support in Long Beach, Los Angeles, and Orange County, and remote service nationwide.
Frequently Asked Questions About Client Accounting Services
Is CAS only for small businesses?
No. The trigger is growth outpacing your team, not a revenue threshold.
Can CAS work alongside our existing accounting staff?
Yes. Many clients keep internal staff and add controller or CFO oversight.
Do we have to switch accounting software?
Not necessarily. We recommend a change only when your system is holding you back.
Can we start with one service and add more later?
Yes. Most clients start with core accounting and add tiers as they grow.
Does CAS include tax preparation?
It’s a separate service, but at Windes it’s coordinated with your CAS team.
Does CAS work for companies with multiple entities?
Yes. Consolidated financials are part of fractional controller support.
Can a CAS team work onsite?
Yes, across Long Beach, Los Angeles, and Orange County.
Talk to the Windes CAS Team
The right CAS engagement lets you hand off the volume and keep the oversight. Windes builds each engagement around how your business actually runs, and we’ve been doing it for 100 years.
Talk to our CAS team or take the Fractional CFO Scorecard to see where your finance function stands.
