January 2026 · Bookkeeping, Small Business, Taxes
The 2026 January Checklist for Arizona Small Businesses
Two hard deadlines, one estimated payment, and the cheapest month to fix your books
January has a reputation for resolutions, but in a small business it is deadline month. A handful of forms and payments come due in the next few weeks, and they carry penalties, so they come first.
1. Get W-2s and 1099s out by January 31
Two forms are due by January 31, which this year means February 2 because the 31st lands on a Saturday:
- W-2s, one to each employee and one set to the Social Security Administration
- 1099-NECs, one to each unincorporated contractor you paid $600 or more in 2025, with a copy to the IRS
There is no automatic extension for either.[1]
Filing late costs $60 per form within the first 30 days, $130 until August, and $340 after that. A single missing 1099 can also be penalized twice, once for the copy the IRS never received and once for the copy the contractor never received.[1] The usual blocker is missing W-9s, which is why we push collecting them before the first check goes out.
One change to note for next January: for payments made in 2026, the 1099 threshold rises from $600 to $2,000.[1]
2. Make the final estimated payment by January 15
The fourth-quarter estimated payment for 2025 is due January 15, and it is the last payment that counts toward your safe harbor, the rule that protects you from underpayment penalties.[2] The year-end checklist explains the safe harbor in two paragraphs.
3. Renew the TPT license before penalties start
Arizona TPT licenses came due January 1, and late fees start after January 31. Renewal takes minutes on AZTaxes.gov, so do it before the deadline gets close.
4. Start this year's mileage log now
Mileage is deductible only if it is logged, and a log started in January covers every business mile the year produces. The 2026 rate is 72.5 cents a mile, up from 70 last year.[3] Receipts work the same way: one folder for 2026, photographed as they happen.
5. Use the windows that are open now
The S-corp election window for 2026 is open now and closes March 15, and the myths post covers why that date matters more than most owners expect. If you would rather be reminded than remember, the monthly newsletter flags each deadline as it approaches. January is also the cheapest month to fix messy books, because the pile only grows from here, and catch-up bookkeeping is priced by the size of the pile.
The bottom line
Send the forms, make the payment, renew the license, and start the log. The rest of 2026 inherits a clean foundation.