Quick answer: No. REV-1611 is an official Pennsylvania interest-rate and calculation-method notice, not a return or payment form to fill out. Use its annual and daily rates to calculate interest when instructions require it, then report or pay the result on the applicable tax return, notice response or payment channel.
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 taxpayers calculating statutory interest on late tax |
| What it does not cover | A tax return, amended return, payment voucher, protest, or penalty-waiver request |
| Where it is handled | Use the form or online payment process for the underlying tax; keep REV-1611 as a reference |
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.
- Identify the tax type, due date, payment date and unpaid tax principal before calculating interest.
- Use the REV-1611 rate for each calendar-year segment; a delinquency spanning years can require more than one rate.
- Apply the daily rate and day count using the Department's published method.
- Calculate penalty separately because REV-1611 does not make every addition to tax an interest charge.
- The Department's notice or calculator can control the billed balance; reconcile differences before paying or protesting.
Practical example
A $2,000 tax balance remains unpaid across December and January. The taxpayer divides the delinquency into calendar-year segments, applies each year's published daily rate to the relevant days, and pays the total through the correct tax account. The taxpayer does not mail REV-1611 itself.
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
- Confirm the original due date and tax principal.
- Download the current REV-1611 notice.
- Split days when the annual rate changes.
- Compute interest and penalties separately.
- Use the correct return, voucher or online account to report and pay.
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
- Searching REV-1611 for signature or taxpayer-information fields.
- Using one year's rate for a delinquency spanning multiple rate periods.
- Calculating interest on penalty without confirming statutory instructions.
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, tax deadline guide. Read related pages as a topic cluster, but follow the year-specific official form for the return you actually file.
Frequently asked questions
Where is REV-1611 filed?
It is not filed. It is a reference notice for interest calculations.
Does REV-1611 calculate late-filing penalty?
No. Penalty rules are separate and depend on the tax and filing facts.
Can the Department calculate interest?
Often the Department or online system will compute a balance, but taxpayers should keep an independent reconciliation.
Sources reviewed
Last reviewed: August 15, 2026. This article provides general educational information, not individualized tax, legal, investment or benefits advice.