To outsource bookkeeping for CPA firms work before busy season, start by December. Partnership and S corporation returns for tax year 2026 are due Monday, March 15, 2027. A pilot takes 4 to 6 weeks to settle, so December leaves room to fix problems before the rush.
Last updated October 17, 2026. Reviewed by Aryan Patel, founder of Senvora Group, a bookkeeping firm that supports CPA firms and business owners in the US and Canada. Due dates below come from the IRS draft Publication 509 for 2027, so check the final version when the IRS publishes it. Here is a timeline, what to hand off, what to keep and how to run a small pilot.
Short on time before busy season? A 30 day pilot with a bookkeeping partner lets your firm test the fit on a few clients first.
One legal check belongs on the list too: IRC 7216 consent when bookkeeping goes offshore.
Key takeaways
- Form 1065 and Form 1120-S for tax year 2026 are due Monday, March 15, 2027. Extended: September 15, 2027.
- Form 1040 and Form 1120 are due Thursday, April 15, 2027, per the IRS draft 2027 calendar.
- From October 17 there are about 21 weeks until March 15.
- Hand off the repeatable work first: bank feeds, reconciliations, cleanup and month end close. Keep advice and sign off.
- Start with a pilot of 3 to 5 clients. Do not move your whole book in January.
Why busy season is the wrong time to try this
Most firms wait until they are already drowning. That is the worst moment. A new hire or a new vendor needs training, and training eats the exact hours you do not have in March.
Hiring is not getting easier either. In the AICPA PCPS CPA Firm Top Issues Survey in 2024 (667 respondents), finding qualified staff was the number one issue for firms with two or more employees. The coverage we read did not publish a percentage, so we will not quote one.
A timeline that works backward from March 15
| Window | What to do | Why |
|---|---|---|
| Now to Nov 15 | Pick 3 to 5 clients with messy or late books. List what you hand off and what you keep | Small pilot, real problems, low risk |
| Nov 15 to Dec 15 | Run the pilot. Get the books closed through October or November | You see quality and turnaround before the rush |
| Dec 15 to Jan 15 | Review the first closes. Fix the process. Add more clients if it went well | You still have time to change vendors |
| Jan 15 to Feb 15 | Year end close and 1099 prep. Form 1099-NEC and W-2 are due Monday, February 1, 2027 | Clean books feed your returns |
| Feb 15 to Mar 15 | Your team reviews and files. The outsourced team stays on bookkeeping | Your hours go to returns, not reconciliations |
The February 1, 2027 date for Form 1099-NEC and W-2 comes from the IRS employment tax due dates page. The entity dates come from the IRS first quarter tax calendar for 2026 and the draft 2027 calendar. In 2026 entity returns were due Monday, March 16, because March 15 fell on a Sunday. In 2027 March 15 is a Monday.
What to hand off and what to keep
Hand off work that repeats every month and follows rules: bank and credit card feeds, reconciliations, categorization, month end close, backlog cleanup and basic reports. Keep the work that needs your license and judgment: tax positions, client advice, review of the final books and sign off on returns.
In the QuickBooks files we review, the problems we see most are the most common setup problem was no bank rules at all, in of files. Mixed personal and business spending, unreconciled history and a wrong start date show up again and again. Those are exactly the problems that eat your February. Read the full 5 QuickBooks setup errors we see most to see what each one looks like.
If a client is years behind, start with our retroactive bookkeeping guide. If you want the books closed on a schedule, see how we run the quarter end close checklist.
Questions to ask before you sign
- Who touches client files, and where are they based?
- How is client data protected and who has access?
- How is taxpayer information handled? Preparers have consent rules under 26 USC 7216 and 26 CFR 301.7216-3.
- What is the turnaround on a monthly close?
- Who answers when a client calls you with a question?
- Can we start with a pilot and leave without a long contract?
For white label work, also ask how the vendor stays invisible to your clients. We cover that in our white label bookkeeping guide.
What a good pilot looks like
A pilot needs one clear goal: books closed by a set day each month, with fewer follow up questions than before. Write down how many hours your team spends per client today. Measure again after two closes. If the number drops and the books are clean, add clients. If not, you learned that with 3 clients and not 30.
Frequently asked questions
When should a CPA firm start outsourcing bookkeeping before busy season?
Start by December. Entity returns for tax year 2026 are due March 15, 2027, so a December start gives you about 3 months to run a pilot and fix problems before the rush.
What should a CPA firm keep in house?
Keep tax advice, review of the final books and return sign off. Outsource the repeatable monthly work: feeds, reconciliations, cleanup and close.
How many clients should a CPA firm start with?
Start with 3 to 5. Pick clients with late or messy books so you see real quality, not a best case.
Can a CPA firm outsource bookkeeping and still protect client data?
Yes, but ask the vendor how they protect files and who has access. Tax return information has consent rules under 26 USC 7216, so get written answers before you start.
Will my clients know I outsource bookkeeping?
Not if you use a white label setup. Ask any vendor how they stay invisible and who your client contacts.
Sources
- IRS draft Publication 509 for 2027 (irs.gov)
- IRS first quarter tax calendar (irs.gov)
- IRS employment tax due dates (irs.gov)
- 26 CFR 301.7216-3 (law.cornell.edu)
- AICPA PCPS CPA Firm Top Issues Survey 2024, reported by CPA Practice Advisor
Want a pilot plan for your firm?
Senvora Group runs monthly closes for CPA firms and business owners. See our CPA firm support service or send a message, or DM Aryan with your client count. Which client costs your team the most hours every month?
