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Pennsylvania Form PA-40 X – Amended Individual Income Tax Return (2026)

Last reviewed: 2025-11-09

Use the Pennsylvania Tax Form Calculator Pennsylvania Form PA-40 X – Amended Individual Income Tax Return as a stand alone tax form calculator to quickly calculate specific amounts for your 2026 Pennsylvania state tax return. Alternatively, you can use one of our Combined Federal and State Tax Estimators to quickly calculate your salary, tax, and take-home pay.

Form PA-40 X is the Amended Pennsylvania Individual Income Tax Return used to correct previously filed income, credit, or payment information. Taxpayers file this form when an original return requires adjustment due to updated income data, IRS changes, or discovered omissions. Each section must report both original and amended figures side by side for transparency.

The form recalculates tax due using Pennsylvania’s flat 3.07% rate and applies penalties and interest for underpaid balances where applicable. You must explain the reason for the amendment clearly in Section I.

When to File an Amended Return

Always attach supporting documentation (such as revised schedules or federal Form 1040-X) when submitting this form. Retain copies of both the original and amended returns for your records.

Pennsylvania PA-40 X — Amended Income Tax Return (2026)
SECTION I — REASON FOR AMENDMENT
1Reason for filing amended return
SECTION II — ORIGINAL VS. AMENDED AMOUNTS
Original / Amended
2Total PA Taxable Income /
3PA Tax Liability (3.07%) /
4Total Payments and Credits /
5Balance Due (Line 3 − Line 4) /
6Refund (if Line 4 > Line 3) /
SECTION III — ADJUSTMENTS
7Penalty for underpayment (5%)
8Interest due (2%)
9Total Amount Owed (Line 5b + Lines 7 + 8)
10Overpayment (if applicable)

Examples

Example 1 – Underreported Income: You discovered an unreported $5,000 in self-employment income. The amended return increases taxable income by that amount, recalculating PA tax at 3.07%, and adds a small penalty and interest using Lines 7 and 8.

Example 2 – Corrected Withholding: After receiving a revised W-2, your PA tax withheld rises from $1,200 to $1,500. The amended return now shows a refund on Line 10 instead of a balance due.

Filing Tips

Last reviewed: 2025-11-09: If you believe this form requires an update, please contact us.

Related Forms and Resources

Form PA-40 X ensures taxpayers maintain compliance and accuracy with Pennsylvania’s flat income tax system. Promptly filing an amendment prevents penalties, supports faster processing, and safeguards refund eligibility.

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Frequently Asked Questions

What is Form PA-40?

Form PA-40 is the Pennsylvania Individual Income Tax Return used by residents, part-year residents, and nonresidents to report taxable income and claim credits or deductions.

Can I amend to claim a refund?

Yes, if withholding or estimated payments exceeded revised liability.

Does PA tax long-term capital gains?

Yes—PA taxes “net gains from the sale, exchange, or disposition of property.” This wage page doesn’t include capital gains; model them with Schedule D.

What rate does Pennsylvania use?

Pennsylvania has a flat personal income tax rate of 3.07 % for all taxable income.

Where do I enter the exclusion amount?

You do not enter it separately; if fully excluded, you simply omit the gain from your PA-40. Partial exclusions must be shown on Schedule 19.

Important Notes

All calculations are estimates for guidance only. Always review your return and consider professional advice when submitting official filings.