Quick answer: PA-40 Schedule G-L calculates a Pennsylvania resident's credit for income tax paid to another state on the same income. Match each state's taxable income to the corresponding Pennsylvania income class, compute Pennsylvania tax on that income, and claim no more than the allowed lesser amount.
This guide explains the federal or state rule in practical filing terms. It uses the latest official material available on August 15, 2026; always use the form and instructions for the tax year you are filing because line numbers, limits and procedures can change.
At a glance
| Question | Practical answer |
|---|---|
| Who this applies to | Pennsylvania residents taxed by Pennsylvania and another state on the same income |
| What it does not cover | Local earned income tax, tax paid on income Pennsylvania does not tax, or a credit for a nonresident's home state without reciprocity analysis |
| Where it is handled | Attach Schedule G-L, the other-state return and required wage statements to PA-40 |
How the rule works
Start with the legal character of the payment, transaction, benefit or form—not the label used in an advertisement or summary. Tax results can differ when ownership, timing, filing status, residency, basis, participation or documentation changes. The controlling return instructions should be reconciled with all information statements before filing.
- Prepare the other-state return first so the final tax—not merely withholding—is known.
- Identify income actually taxed by both jurisdictions in the same taxable year.
- Translate the overlapping income into Pennsylvania's separate income classes.
- The credit is limited and cannot exceed the Pennsylvania tax attributable to the double-taxed income.
- A separate schedule may be required for each state, and reciprocal wage agreements can change the filing route.
Practical example
A Pennsylvania resident earns consulting income in another state. The other state taxes $20,000 and imposes $900 of final income tax; Pennsylvania tax attributable to the same income is $614. The credit is generally limited to $614, not the $900 paid elsewhere, subject to Schedule G-L instructions.
The example isolates the main rule and is not a tax calculation for every fact pattern. Other income, deductions, state conformity, related-party rules and prior-year carryovers can change the final result.
Step-by-step checklist
- Complete all nonresident returns.
- List income taxed by both states.
- Classify it under Pennsylvania law.
- Calculate the other-state and Pennsylvania limitations.
- Attach the complete other-state return and required statements.
Keep copies of the filed return, schedules, source documents, calculations and submission confirmation. If an issuer or agency document is wrong, request a correction instead of silently changing a number without an explanatory record.
Common mistakes to avoid
- Using other-state withholding instead of final tax liability.
- Claiming credit for income not taxed by Pennsylvania.
- Failing to attach the other-state return, which can cause disallowance.
A tax software interview can help transfer information, but it cannot verify an uncertain legal classification or recreate missing evidence. Pause and obtain advice from a credentialed tax professional or the responsible agency when the dollars are material or the facts are unusual.
Related NavajoTax guides
For connected planning and reporting issues, see PA-40 Schedule W-2S, financial research process. Read related pages as a topic cluster, but follow the year-specific official form for the return you actually file.
Frequently asked questions
Does the credit refund all tax paid to the other state?
No. It is limited by Pennsylvania tax attributable to the same income and other rules.
What if two other states tax the income?
Complete the required computation for each state and prevent duplicated income or credits.
Does Schedule G-L cover local taxes?
It generally addresses qualifying income tax paid to another state or specified jurisdiction; local-credit rules are separate.
Sources reviewed
Last reviewed: August 15, 2026. This article provides general educational information, not individualized tax, legal, investment or benefits advice.