A Form 2290 is filed for the weight category a truck is in when it's first used. If its taxable gross weight later goes up and it lands in a new, heavier category, the IRS wants the extra tax for the rest of the period. That is a taxable gross weight increase amendment, and it is one of only two reasons the IRS lets you check the Amended Return box — the other is a suspended vehicle that went over its mileage limit.
What counts as a weight increase
Taxable gross weight is the truck fully equipped for service, plus the trailers customarily used with it, plus the maximum load customarily carried. The IRS's own example of an increase is a change in the maximum load customarily carried. If a change like that moves the truck into a higher category, you file. If it stays in the same category, there is nothing to report. See how to work out taxable gross weight and the weight category table.
It only works one way. The IRS allows no credit, lower tax, or refund for an occasional light or decreased load, or for a discontinued or changed use of the vehicle.
When the amendment is due
File the amended Form 2290 and Schedule 1 by the last day of the month following the month the taxable gross weight increased. As with every 2290 deadline, a date that falls on a Saturday, Sunday, or legal holiday moves to the next business day — the Form 2290 due date calculator shows the IRS dates for each month.
How the additional tax is figured
The IRS gives a four-line worksheet, and you attach a copy for each vehicle:
- Enter the month the taxable gross weight increased. Write the same month next to the Amended Return box on page 1.
- Find that month in the IRS Partial-Period Tax Tables and read down to the new category. That is the new tax.
- Under the same month, find the tax for the category you previously reported.
- Subtract line 3 from line 2. That is the additional tax, entered on Form 2290, line 3.
A worked example using the IRS's printed Table I figures: a truck reported in category T has its maximum load increased in January 2027, putting it in category V.
| Worksheet line | Amount |
|---|---|
| 1. Month the weight increased | January 2027 |
| 2. New category V, January column (Table I) | $275.00 |
| 3. Previous category T, January column (Table I) | $259.00 |
| 4. Additional tax (line 2 − line 3), to Form 2290 line 3 | $16.00 |
That amendment is due by the end of February 2027 — and because February 28, 2027 is a Sunday, the IRS chart moves it to March 1, 2027. Logging vehicles use the logging table (Table II) instead.
One exception: if the increase happens in July, after you've already filed, use the full-period amounts on Form 2290 page 2 for the new category instead of the partial-period tables. For example, moving from category T to V in July is $550.00 − $518.00.
The amendment is a short return: reason, month, VIN, old and new category. Create a free account to start it.
Filling in the return
- Report the additional tax on line 3, not line 2. Only put tax on line 2 if you're also reporting other taxable vehicles on the same return.
- Check the Amended Return box and write the month the weight increased next to it.
- List the vehicle on Schedule 1 — an amended return with no VIN on Schedule 1 is rejected (rule F2290-033-01).
- Attach the worksheet. The IRS rejects an e-filed return with an amount on line 3 but no worksheet (F2290-002-01), without the Amended Return box checked (F2290-003-01), or where the worksheet's additional tax isn't line 2 minus line 3 (F2290-018-01).
How to file it here
- Start a return for the business and choose Amended return.
- Pick the reason: Taxable gross weight increased.
- Enter the month of the increase, each truck's VIN, its previous category, and its new category. Several trucks can go on one amendment.
- The additional tax is figured from the IRS partial-period table, line by line, and the worksheet goes with the return.
- Pay, e-sign, and submit. The accepted amendment comes back with a stamped Schedule 1.
For the other amendment types and how they differ from a VIN correction, see the Form 2290 amendments guide.