Moves you can still make after year end
- SEP-IRA / traditional IRA contribution. Generally allowed up to the filing deadline and counts for the prior year, lowering taxable income directly. The biggest true last-minute lever.
- HSA contribution if you had an eligible high-deductible health plan, also allowed up to the deadline.
Deductions people forget to claim
- Home office, simplified method is $5 per square foot up to 300 sq ft.
- Mileage, 72.5 cents per business mile for 2026, if you kept a log.
- Self-employed health insurance premiums, deducted above the line.
- The QBI deduction, up to 20% of net business income on Form 1040.
- Phone and internet, the business-use share.
- Startup costs, up to $5,000 in your first year.
Fix your “Other expenses” before filing
Anything dumped into a generic “Other” bucket is a deduction at risk. Take a few minutes to move each expense into its correct Schedule C category so it is fully claimed and clearly documented. If your receipts are already categorized, this is a quick review instead of a scramble.
Do not leave deductions on the table at the deadline. NeoReceipt keeps every receipt sorted for Schedule C, so filing is fast and complete.
Try NeoReceipt freeWhat you can no longer do once the year has ended
Some deductions have to happen inside the tax year, so it helps to know which doors have already closed. You generally cannot create a new business expense for last year after December 31, you cannot make a solo 401(k) employeedeferral for a year that has ended, and you cannot deduct equipment you buy this year against last year's income. What still works after year end are the contributions the IRS specifically lets you backdate to the filing deadline, chiefly a SEP-IRA, a traditional IRA, and an HSA.
That is why the last-minute game is mostly about claiming deductions you already earned rather than creating new ones. Go line by line through your receipts and mileage and make sure every real expense is counted and filed under the right Schedule C category, because an uncategorized or forgotten expense is simply a deduction you paid for and did not use.
Not ready? File an extension
An extension gives you six more months to file, but not to pay. Estimate what you owe with the 1099 tax calculator and pay that by the April deadline to avoid interest and penalties.