Preparing for the 2027 Tax Season: What Accounting Firms Should Get Ready Now

The returns you'll prepare in early 2027 cover tax year 2026, and it's the first season where several changes from the 2025 tax law (the One Big Beautiful Bill Act) appear on the documents clients send you. Some items will be new to clients, some forms will look different, and some forms clients used to receive won't arrive at all.

The firms that have a calm February are the ones that update their requests in the fall. This guide covers what changes for 2026 returns, how your client document checklist should change, the key 2027 dates, and the firm-level work to finish before January.

What's different for 2026 returns

• New W-2 codes. The 2026 Form W-2 reports cash tips (Box 12 code TP), qualified overtime (code TT), and a tipped occupation code (Box 14b). These support the tips and overtime deductions, so you'll be reading W-2s more closely than before.
• A charitable deduction for non-itemizers. Starting in 2026, taxpayers who take the standard deduction can deduct up to $1,000 ($2,000 married filing jointly) of cash gifts to qualifying charities. Clients who never sent donation receipts before now have a reason to.
• A new floor for itemizers. Itemized charitable gifts only count above 0.5% of AGI, which changes the math for clients who give a little every year.
• A higher SALT cap. The state and local tax deduction cap is $40,400 for 2026, phasing down for higher incomes. More clients may benefit from itemizing, so property tax and state payment records matter again.
• Deductions that started in 2025 continue: the additional deduction for taxpayers 65 and older, and interest on qualifying loans for new U.S.-assembled vehicles.
• Fewer 1099s. The 1099-NEC and 1099-MISC threshold rises to $2,000 for 2026 payments, and the 1099-K threshold is back to $20,000 and more than 200 transactions. The income is still taxable; clients just won't get a form for it.
• Higher dependent care FSA limit: $7,500 starting in 2026.

Update your client document checklist

Each of those changes turns into a request. Before you send organizers or engagement packets, add these items:

• All Forms W-2, with a note asking clients in tipped or hourly roles to check that tips and overtime appear. Errors here are easier to fix with the employer in February than in April.
• Cash donation receipts or acknowledgments for every client, not just itemizers.
• Property tax bills and state estimated payment records for clients near the itemizing line.
• Lender interest statements and purchase details (including the VIN) for clients who bought a new vehicle with a loan.
• Income records for side work, gig platforms, and online sales: platform earnings summaries, bank deposits, or invoices. With higher 1099 thresholds, “I didn't get a form” no longer means “I had no income.”
• For business clients: a year-end vendor report and W-9s for contractors paid $2,000 or more.
• Direct deposit details. The federal government has been phasing out paper refund checks, so confirm the account clients want refunds sent to.

For the rest of the list (brokerage statements, K-1s, mortgage interest, HSA forms, prior-year returns), see our client document checklist.

Key 2027 dates

• January 15, 2027: fourth-quarter 2026 estimated tax payments.
• February 1, 2027: Forms W-2 and 1099-NEC due to recipients and to the SSA/IRS (January 31 falls on a Sunday).
• Mid-February: brokerage and consolidated 1099s usually arrive. Expect corrected forms after that.
• March 15, 2027: partnership (Form 1065) and S corporation (Form 1120-S) returns or extensions for calendar-year entities.
• April 15, 2027: individual and C corporation returns or extensions, and first-quarter 2027 estimates.
• September 15 and October 15, 2027: extended business and individual returns.

Firm-level prep for October through December

October–November: plan the season

• Review last season. Which clients sent documents late, which engagements stalled, and where did staff time go? Use it to decide who gets an earlier request or a firmer deadline.
• Update engagement letters and pricing, including how you'll handle late documents and rush work.
• Renew PTINs (they expire December 31) and confirm EFIN and e-file details.
• Review your written information security plan. The FTC Safeguards Rule requires one, and the IRS expects preparers to have it.

December: get the requests ready

• Update organizers and questionnaires with the new 2026 items above.
• Build each client's request from their prior-year return, so it lists the documents that client actually had, not a generic list.
• Get clients set up in your portal before January, so the first message they get from you isn't a login problem.

January: send early, then follow up on what's missing

Send requests in early January, before forms arrive, so clients know what to watch for. Then follow up only on outstanding items, on a fixed schedule. Our guide to chasing clients for tax documents has a cadence that works.

Still closing the year for bookkeeping clients? See closing the books in October for the Q3 close and early year-end prep.