2026 tax year · Filing season 2027
Year-End and Tax Season Checklist
What closes on December 31, what is due in January and February, and what to have ready when filing season opens. Each step links to the page on this site that covers it in full, and every date comes from our tax deadline calendar.
Seven steps, in calendar order
Dates are federal deadlines for calendar-year filers. When a deadline falls on a Saturday, Sunday or legal holiday it moves to the next business day, and the IRS occasionally postpones deadlines for federally declared disaster areas. The tax deadline calendar lists every date for the year.
- 01Before 31 December 2026
Year-end tax planning
Entity elections, the timing of income and deductions, charitable gifts and most retirement plan actions have to be executed inside the tax year. After December 31 the 2026 return largely reports a settled set of facts, so this is the step with the most room left in it.
- 02Before 31 December 2026
Retirement plan contributions
Which plan fits, SEP, SIMPLE or solo 401(k), depends on whether you have employees and how much you want to put away. A solo 401(k) is a year-end matter rather than an April one, so it has to be decided before December 31. A SEP can still be set up after the year ends, up to the extended due date.
- 03Before 31 December 2026
Catch up the books
Catching up is a normal starting point, not a problem to be embarrassed about. Where a year is incomplete or has never been reconciled, that clean-up is the first piece of work, because reporting on an unreconciled file produces confident-looking numbers that are wrong.
- 0415 January 2027
Q4 estimated tax payment
The final estimated payment for the 2026 tax year, for individuals, sole proprietors and pass-through owners. Paying the right amount at the right time avoids penalties without lending money to the IRS interest-free.
- 051 February 2027Deadline reminder
W-2 and 1099-NEC deadline
Employers, and businesses that paid contractors, must furnish these forms to recipients and file them. The statutory date is 31 January, which falls on a Sunday in 2027, so it moves to the next business day.
- 06Filing season 2027
Documents and a free consultation
Nobody arrives with everything, and you do not need to: gather the last two or three filed returns, income documents, business records and property records, and the gaps are part of the conversation. Send documents through the client portal rather than by email. The initial consultation is free.
- 07Whenever one arrives
An IRS or SCDOR notice
A letter from the IRS or the South Carolina Department of Revenue carries a response deadline, so it is worth raising early rather than after filing season. Keep the whole notice, both sides: the notice number in the corner determines what happens next.
Year end and tax season: common questions
The questions that come up between December and the April filing date.
What has to be done before December 31?
Anything that has to be executed inside the tax year: entity elections, the timing of income and deductions, charitable gifts and most retirement plan actions. After December 31 the return largely reports a settled set of facts. Tax planning and advisory is the work that happens while those decisions are still open.
Can I still set up a retirement plan after the year ends?
Some, not all. A solo 401(k) is a year-end matter and has to be decided before December 31. A SEP can still be set up after the year ends, up to the extended due date, and IRA and HSA contributions for 2026 can be made until 15 April 2027. Which plan fits.
When is the last estimated payment for the 2026 tax year?
15 January 2027. It is the fourth and final estimated payment for 2026, for individuals, sole proprietors and pass-through owners. The first payment for 2027 is due on 15 April 2027, the same day as the 2026 return. See the tax deadline calendar.
Why are W-2s and 1099-NECs due on 1 February in 2027?
The statutory date is 31 January, which falls on a Sunday in 2027, so the deadline moves to the next business day. By then the forms must be furnished to recipients and filed. The tax deadline calendar has the rest of the winter dates.
Should I catch up my books before the year closes?
If they are behind, yes. Where a year is incomplete or has never been reconciled, that clean-up is the first piece of work, because reporting on an unreconciled file produces confident-looking numbers that are wrong. Bookkeeping services.
What should I gather for filing season?
The last two or three filed returns, income documents such as W-2s and 1099s, business financial statements, and property records. Send them through the client portal rather than by email. The document checklist is organized by the kind of return you file.
What if a notice from the IRS or the SCDOR arrives during tax season?
Do not wait for filing season to end. Notices carry response deadlines, and the notice number in the corner determines what happens next. Keep the whole notice, both sides, and see tax controversy and IRS representation.
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