2026 IRS & Payroll Changes That Can Trip Up Small Businesses (Including Overtime + the New Postmark Problem)
If you’re a small business owner, you don’t need more rules to remember. You need the handful of changes that can quietly cost you money (or cause a nasty “late” notice) if you miss them.
And for 2026, one of the biggest “gotchas” isn’t even an IRS form… it’s how your mail gets postmarked.
Here are the 2026 updates I want every business owner to have on their radar—without the jargon.
1) IRS inflation adjustments for 2026 (the numbers moved again)
The IRS released inflation adjustments for tax year 2026, which affects things like standard deductions and bracket thresholds.
Why you should care (even if you “don’t itemize”):
If your business is a pass-through entity (sole prop/LLC/S-corp), your business profit impacts your personal tax return.
Updated thresholds can change how much you should set aside for taxes and how estimated payments feel throughout the year.
Quick headline numbers (standard deduction for 2026):
Married filing jointly: $32,200
Single / married filing separately: $16,100
Head of household: $24,150
Practical tip: If you use a “percentage of income” rule for tax savings, keep it—but do a quick reset in January so you’re not underpaying all year.
2) 2026: A new wrinkle for the QBI deduction (Section 199A)
If your business is eligible for the Qualified Business Income (QBI) deduction, there’s a new eligibility wrinkle starting for tax years beginning after December 31, 2025.
What to do with that information:
Don’t panic.
Do flag it for your tax pro early (January/February), especially if your profit fluctuates or you’re near any thresholds.
Practical tip: If you’re not sure whether you qualify for QBI, ask now—don’t wait until March when everyone is buried.
3) Overtime rules for 2026: don’t assume the federal threshold changed
This one’s confusing because headlines come fast and court cases move faster.
Here’s the bottom line for most small businesses:
The federal salary threshold to classify certain employees as “exempt” from overtime remains $684/week (as of going into 2026).
States can be stricter (and many are). So you need to follow whichever rule is more employee-friendly: federal or state.
Practical tip: If you have salaried employees and you’re not 100% sure they’re classified correctly, do a quick payroll audit:
Who is salaried?
Who is classified as exempt vs non-exempt?
What state rules apply where they work?
Do job duties actually match the exemption category?
This is one of those areas where “we’ve always done it this way” can get expensive.
4) The postmark change that could make “on-time mail” look late
Here’s the one I really want you to remember:
Starting late December 2025, USPS clarified that a postmark may reflect the date of first automated processing and NOT necessarily the date you dropped it in the mailbox.
So if you mail something on a deadline day and it doesn’t get processed until the next day (or later), the postmark can make it look late.
This matters for things like:
Paper-filed tax returns
Checks mailed to the IRS
Time-sensitive IRS responses
Year-end charitable donations (where the postmark matters)
How to protect yourself (my “don’t get burned” list)
If you must mail something time-sensitive:
Go inside the post office and ask for a manual (hand) postmark
Get a dated acceptance proof (receipt / validation label)
Use Certified Mail if you need documentation
Consider an IRS-approved Private Delivery Service (PDS) option when appropriate
Best option: e-file + e-pay whenever you can
My strong opinion: If a deadline matters, don’t use the blue collection box on the last day. That’s chaos roulette now.
Mini example (real-world scenario)
Let’s say you’re mailing a payroll tax payment, an IRS response, or a charitable gift on a hard deadline. You drop it in a collection box at 6:00 PM on the due date, feeling proud and responsible… and the mail doesn’t get processed until the next day. Suddenly your postmark is dated one day late, and you’re stuck proving what happened.
Instead, you walk into the post office, ask for a manual postmark, get a receipt, and move on with your life. That tiny step can save you hours of stress later.
If you want a clean, simple plan for 2026—estimated taxes, payroll compliance, deadlines, and a “what to keep” checklist—book a quick call and we’ll map it out.
Book here: https://calendly.com/sara-dunhambookkeepingservices
