Tax planning · Guide
Quarterly Estimated Taxes for PTs: Stay on Track All Year
How estimated payments work, when they're due, how to calculate them, and a simple system that keeps cash flow steady.
One of the biggest adjustments when you go from employed PT to practice owner or contractor is how taxes get paid. On someone else's payroll, tax is withheld from every paycheck. Once you're self-employed, that responsibility is yours, and it runs on a quarterly schedule. Once you understand it, it's easy to manage.
Why estimated payments exist
The U.S. tax system is pay-as-you-go. The IRS expects tax to be paid through the year as income is earned, not all at filing time. If you earn income without withholding, such as contract income, you make four estimated payments based on your expected income and expenses.
The standard due dates
- Q1 (January to March): April 15
- Q2 (April and May): June 15
- Q3 (June to August): September 15
- Q4 (September to December): January 15 of the following year
When a date falls on a weekend or holiday, the deadline moves to the next business day. Many states have their own estimated tax schedules, so check those too.
How to calculate what to pay
There are two reliable approaches. The first is the prior-year safe harbor: pay at least 100% of last year's total tax, in four equal payments (110% if your adjusted gross income was over $150,000). It's predictable, and you know the number in advance.
The second is to estimate this year's tax from projected income and expenses. It's more precise when your income has changed a lot, and may mean smaller payments in a slower year. If your income arrives unevenly, a method that follows income through the year can also help.
Key takeaway
Pick one method at the start of the year and review it each quarter. Adjust when income changes, rather than waiting for filing time.
A simple system
Open a separate savings account for taxes and move a set percentage of each payment you receive into it. The right percentage depends on your structure, deductions, and total income, so we help you set it and revisit it as the year unfolds. When a payment is due, the money is already there.
If you're a practice owner with an S-corp election, you may be able to cover some or all of your tax through withholding on your own salary (see the S-corp election guide), which can reduce or replace estimated payments.
How to pay
Federal payments can be made online through IRS Direct Pay or your IRS online account, or by mail with Form 1040-ES. Keep a record of each payment, since it's needed when we prepare your return.
If you miss one
Underpaying can lead to a modest penalty based on how much was underpaid and for how long. The best response is to get current and make the next payment on time. Having someone track your payments through the year makes this rare.
Want this applied to your numbers?
We calculate your estimates, remind you of each due date, and keep your books current. Book a 30-minute call and we'll look at your situation together.
Book a 30-minute callThis guide is general information, not individualized tax or legal advice. Rules change and your situation may differ. Talk to a qualified professional before acting. Figures reflect 2026 rules at the time of writing.