Today is Tuesday, September 8, 2026. The third federal estimated tax payment for calendar year 2026 is due on Tuesday, September 15. For households in San Rafael, Marin County, Sonoma County, and Napa County, that date is a planning checkpoint, not a surprise. If some of your income does not already have enough tax taken out through a paycheck, this is the week to confirm the number, the payment method, and the cash that will cover it.
The Putney Financial Group works with people who want a clear path toward financial independence in Northern California. Estimated tax is a cash flow and recordkeeping job. It is not a market call and it is not a promise about results. It belongs in the same conversation as retirement savings, investment withdrawals, and the documents that say who owns what.
Start with a simple question. How much federal tax do you still expect to owe for 2026 after subtracting tax already withheld and refundable credits you reasonably expect? The Internal Revenue Service explains who generally must make estimated payments, how to figure them, and how to send them on its estimated taxes guidance page. Read that page before you treat last April as a standing order. Many people must pay estimated tax if they expect to owe at least 1000 dollars when they file, and if withholding plus credits will be less than the smaller of 90 percent of this year tax or 100 percent of last year tax. Higher income filers can face a 110 percent prior year test. If your facts are unusual, use the worksheet in Form 1040 ES and Publication 505 rather than a hallway guess.
September 15 covers income from June 1 through August 31 for people on a calendar year. That window often looks different from the first half of the year in this region. A consulting invoice may have been paid in July. A rental deposit may have become taxable income. A partnership or S corporation K 1 estimate may have changed. A brokerage account may have realized gains you did not plan in March. A retirement distribution may have been larger than the withholding on the form. Those events are reasons to rerun the worksheet instead of sending the same amount you sent in June.
Write down every income stream that is not fully covered by paycheck withholding. Include interest, dividends, capital gains you already took, rental income, business profit, gig work, taxable Social Security, pension income without enough withholding, and trust or estate distributions. Then write the tax already paid: withholdings, prior estimated payments in April and June, and any extra withholding you asked an employer or payer to take. The gap is the number that has to be funded by September 15 if you are using the equal installment method. If your income arrived unevenly, the annualized installment method may produce a different amount, but only if you can document the months.
Cash flow in Marin and the North Bay has its own September texture. Property tax installments, insurance renewals, school costs, and leftover summer travel can sit next to the tax payment on the same calendar. A household that looks liquid on a brokerage screen can still be tight in the checking account that pays the IRS. Decide this week which account will send the payment. If you will sell a position to raise cash, ask what tax that sale itself may create. If you will use a cash reserve, confirm the transfer will settle before the due date. Online IRS payments record a date. A check in the mail uses the postmark. Do not leave that choice until Monday night.
Business owners who are not on a salary should treat estimated tax as payroll for the owner, not as leftover cash. Recast year to date profit with a conservative remaining year, then compare that picture to last year tax. If you pay yourself a wage from an S corporation, confirm that wage withholding is actually running. Estimated payments and wage withholding are different pipes. Mixing them in your head is how January becomes a scramble.
Households with wages still need this week if they also have investment income, rental activity, or a side business. Extra withholding on a paycheck can replace some estimated payments, but only if the extra amount is large enough and starts soon enough. Changing a withholding form in mid September does not retroactively cover June through August. It can help the remaining months. Keep a copy of what you submitted and a note of the first paycheck that will show the change.
Retirement money belongs in the same sitting. A distribution from an IRA or workplace plan can create taxable income that withholding on the distribution form did not fully cover. Required minimum distributions are a year end item, yet September is when many households still have time to choose which account to draw from and whether to withhold more on the next request. Putney publishes a public retirement planning overview that frames the questions behind those choices: when work income will stop, how lifestyle spending might change, and what you hope to leave for people or charities. Use that page as the reminder that a tax payment and a retirement withdrawal are connected.
If you are still working, confirm that deferrals into workplace plans and IRAs are running as you intended after summer travel or a job change. If you are considering a Roth conversion later in 2026, remember that a conversion is taxable income. Adding one after you have already set September estimates can create a fourth quarter problem. Put the conversion on a calendar with the January 15 payment, not as an afterthought in December.
Investment accounts need a September look for realized gains. The question is whether the tax lot activity already on the 2026 ledger matches the cash you are about to send. If you harvest a loss, confirm it is a real economic sale and that you understand the wash sale rule. If you plan a gift of appreciated shares, the timing and the documentation matter. Those moves should fit a written plan, not a number in a blog post.
That written plan is the service Putney describes on its financial planning page. The process there is an analysis of current circumstances, a discussion of lifestyle and family goals, and a map that can include retirement, investments, insurance, taxes, education, charitable giving, and estate issues. Estimated tax sits inside the tax part of that map. A planner can help you see how a payment, a withholding change, and a withdrawal interact. A planner is not your return preparer unless you have hired that work separately.
Estate and trust items show up in September more often than people expect. A trust distribution can be taxable to a beneficiary. A sale inside an estate or trust can create a K 1 that arrives later than the estimated due date. If you live in Napa County or you keep property or family there, legal documents and tax timing have to be read together. Families who need wills, trusts, powers of attorney, or health care directives can review the Napa Valley estate planning services page from Meghan Avila Law for the legal side of those documents. That is a legal resource, not a Putney product. Bring both maps to the same conversation so a distribution does not surprise the person who has to send the September payment.
If a charitable gift will change your 2026 taxable income enough to change estimated tax, put it on this week list. If the gift is mainly a December item, note it now so January estimates are not built on a year that no longer exists. California households should also confirm the next Franchise Tax Board amount with the same income picture, especially after a move or income in more than one state.
Make a short written packet this week. One page can hold income streams, tax already paid, the September amount, the payment method, the funding account, and the date you sent it. Keep confirmations. If a spouse or a co owner of a business should know, send them the same page. If you work with a tax preparer or a financial planner, send the packet before the due date so advice is not flying blind.
Then do five actions. Recast 2026 income with what actually happened from June through August. Compare the result to the 90 percent and 100 percent tests on the IRS page, including the higher income variant if it applies. Fund the payment from an account you have already chosen, with settlement time included. Review retirement withholding and any planned fourth quarter conversions or gifts. Write the January 15 reminder now, while September is still in front of you.
Putney can talk through how estimated tax, retirement withdrawals, and household cash flow fit a longer plan for Northern California families. Bring the year to date numbers, the last two federal returns if you have them, and the questions you actually need answered. No article can replace your facts, and no article should promise a result. The useful outcome of this week is a payment that matches the year you are actually living, recorded in a place you can find in April.