If I Forgot to File a W2, Can I File It Next Year?
Learn the correct process for addressing omitted W2s to ensure accurate income reporting and tax compliance.
A W2, or Wage and Tax Statement, is a document employers issue to report an individual’s annual wages and the taxes withheld from their paychecks. The Internal Revenue Service (IRS) and state tax authorities use this form to match reported income with their records. It is used for filing tax returns and determining tax liability or refund. The W2 also details Social Security and Medicare taxes withheld, which contribute to future benefit eligibility.
Tax Years and W2 Reporting
A W2 is issued for a specific tax year, reporting income earned and taxes withheld within that calendar year. For example, a W2 received in January 2025 reports income from the 2024 tax year. This means that income and withholding for a particular year must be reported on the tax return for that same year, not a future year. Failing to report a W2 in its proper tax year can lead to the IRS flagging the return, as the employer’s reported income will not align with the individual’s filed income.
Correcting an Omitted W2
If you discover a W2 was omitted from a previously filed tax return, you can correct this by filing an amended return using IRS Form 1040-X, Amended U.S. Individual Income Tax Return. This form allows taxpayers to adjust income, deductions, credits, or filing status for a tax year that has already been filed.
To prepare Form 1040-X, gather the original tax return for the year the W2 was omitted, the W2 itself, and any other relevant tax documents from that year. You can obtain Form 1040-X from the IRS website. When filling out the form, enter the amounts from your original tax return in one column, the corrected amounts based on the omitted W2 in another, and then calculate the difference. You must accurately report the previously omitted W2 income, recalculate your total income, and adjust any corresponding tax liability and withholding amounts. Attach a copy of the omitted W2 to the amended return.
Once Form 1040-X is completed, you must mail it to the IRS. Amended returns generally cannot be e-filed, though for tax years 2020 and later, electronic filing through tax software may be an option. The correct mailing address for Form 1040-X varies by state, so check the IRS website for the address corresponding to your residence. If you are amending returns for multiple years, each amended return should be mailed in a separate envelope.
After submission, you can track the status of your amended return using the “Where’s My Amended Return?” tool on the IRS website; it typically takes 8 to 12 weeks for processing, but can take up to 16 weeks. It can take up to three weeks from the mailing date for the return to appear in the IRS system.
Penalties for Unreported Income
Failing to correct an omitted W2 and underreporting income can lead to penalties from the IRS. The IRS detects discrepancies between employer-reported income on W2s and the income reported on individual tax returns. Upon discovering such a mismatch, the IRS may send a notice to the taxpayer.
Common penalties include failure-to-pay penalties, which can be assessed if additional tax is owed and not paid by the original due date. This penalty is 0.5% of the unpaid taxes for each month or part of a month the tax remains unpaid, capped at 25% of the tax bill. An underpayment penalty may also apply if insufficient taxes were paid throughout the year through withholding or estimated payments.
Interest also accrues on any unpaid taxes from the original due date until the tax is paid in full. The interest rate is determined quarterly and is based on the federal short-term rate plus 3%. These penalties and interest charges can accumulate over time.