Planning for the January Estimated Tax Payment

The fourth quarterly estimated tax payment lands in the middle of January, right after the most expensive month of the year. If you freelance or own a pass-through business in the US, a little planning in late October turns that payment from a nasty surprise into a calm, pre-funded transfer.

If you work for yourself in the US, nobody withholds tax from your income. Instead, you pay as you go through quarterly estimated payments. Three of them arrive during the year, and the fourth arrives in January, covering the final stretch of the previous year. For 2027 income, that final payment is due on 18 January 2028.

The timing is awkward. December is often a month of holiday spending, slower client payments and year-end bills. By the time January comes around, the money you meant to keep for taxes may have quietly gone elsewhere. The good news is that you can see this coming months in advance, which means you can plan for it now, while there is still time to adjust.

A quick note before we start: this is general information, not tax advice. Estimated tax rules have details and exceptions, and state rules differ. Check the current guidance on the IRS website and your state tax agency, and talk with a tax professional about your situation.

How the January payment fits the year

Estimated payments are meant to spread your tax bill across the year as you earn the income. Each payment covers a period of earnings, and the January payment covers the last months of the calendar year. If you had a big fall, with a large project or a strong holiday season, the January payment is where that shows up.

Three things make the January payment different from the others:

• It is your last chance to catch up. If you underpaid earlier in the year, a larger January payment can reduce how much you are short, though it may not erase a penalty for earlier quarters.
• You know more than you did in April. By late fall you have most of the year's numbers, so your estimate can be far more accurate.
• It sits next to other deadlines. W-2s and Forms 1099-NEC go to recipients and the IRS by 31 January, and many businesses are closing their books at the same time. Planning early keeps these from colliding.

Understand the safe harbor rule first

Before you start projecting income, find out whether the safe harbor rule can make your life simpler. In general, if your payments through withholding and estimates add up to at least 100% of the prior year's total tax, you avoid the underpayment penalty, even if you end up owing more when you file. If your prior-year adjusted gross income (AGI) was over $150,000, the figure is 110% of the prior year's tax.

That rule gives you a choice:

• The safe harbor route. Base your payments on last year's tax. It is predictable and easy to calculate. If your income grew this year, you will owe the difference when you file, but generally without the underpayment penalty.
• The current-year route. Base your payments on what you expect to owe for this year. This can mean paying less now if your income fell, but it requires a decent estimate and carries more risk if you guess low.

Project your income for October to December

If you choose the current-year route, or simply want to know how big your spring bill will be, you need a projection. It does not have to be perfect. A careful estimate in late October beats a panicked guess in mid-January.

1. Pull your year-to-date numbers. Get income and expenses through the end of September or October from your bookkeeping.
2. List the work you expect to finish. Include signed projects, retainers, booked events and any seasonal sales you can reasonably expect.
3. Estimate remaining expenses. Add regular costs plus any planned year-end purchases. Remember that buying equipment only affects this year's numbers in certain ways, and the rules on when property counts are specific, so ask your accountant before buying for tax reasons.
4. Calculate estimated profit for the full year. Year-to-date profit plus projected profit for the remaining months.
5. Estimate the tax. Use last year's return as a guide, tax software, or your accountant. Include self-employment tax if it applies to you, and state tax if your state has one.
6. Subtract what you have already paid. The gap is a rough guide to what your January payment, and possibly your April balance, might look like.

A simple projection template

Copy this into a spreadsheet. The numbers below are made-up examples for a freelancer, not real tax rates or recommendations.

If you are using the safe harbor route instead, swap the "Estimated total tax" line for the safe harbor amount based on last year's return, and divide the remainder across what is left.

Set the cash aside before the holidays

Knowing the number is half the job. The other half is making sure the money is still there in January. The most reliable way to do that is to move it somewhere you will not spend it.

Use a dedicated tax account

Open a separate savings account, or a labeled pot in your business bank, and call it something blunt like "Tax: do not touch." Each time a client pays, move a set share of the payment into that account. Many freelancers pick a percentage based on last year's effective tax rate plus a cushion; your accountant can help you choose a sensible figure.

Front-load the transfers

Try to have the full January amount in the tax account by early December. That way, holiday spending, slow-paying clients and year-end bills cannot eat into it. If a client pays a large invoice in November, move the tax portion the same day.

What to do if you cannot cover it

Sometimes the projection shows a payment you simply cannot fund from cash flow. That is stressful, but it is far better to find out in October than on 17 January. You have options.

• Revisit your expenses. Delay non-essential purchases until after the payment, and cancel subscriptions you no longer use.
• Speed up collections. Send statements to clients with open invoices and ask about their last payment run before the holidays.
• Pay what you can. A partial payment generally reduces the shortfall and any penalty compared with paying nothing. Penalties are usually calculated on the amount and time you were short.
• Talk to a tax professional. They can check whether an exception applies to you, how much you might face in penalties, and whether a payment arrangement makes sense if you will owe a large balance in April.

Build a routine for next year

Once you get through this January payment, use it as a reason to set up a routine that makes every quarter easier.

• Add all four due dates to your calendar, with a reminder two weeks before each one.
• Run a short quarterly check. Compare actual profit with your plan and adjust the next payment.
• Automate the tax transfer. Move a fixed share of every client payment into your tax account the day it arrives.
• Keep confirmations together. Save every payment confirmation in one folder so your preparer has them at filing time.
• Review the safe harbor each spring. Once your return is done, you know the new safe harbor figure for the year ahead.

Frequently asked questions

The bottom line

The January estimated tax payment is predictable, which means it is plannable. Check whether the safe harbor applies, project your income for the last months of the year, and move the money into a separate account before the holidays. Then schedule the payment for on or before 18 January 2028 and stop thinking about it.

Spend 30 minutes on it this week. Future you, sitting down to a quiet January instead of a frantic one, will be grateful.