IRS notice codes, decoded
Find the code printed at the top of your letter. Each page explains — from the IRS’s own published pages — what the notice means, what the printed deadline governs, what happens if you ignore it, and how to respond. Every page includes the free deadline decoder.
Income-matching proposals
The IRS's computers matched third-party income reports against your return and are proposing changes. These are proposals, not bills — your response decides what happens.
Balance-due & collection ladder
The IRS says a balance is unpaid. These run in a published sequence, from the first bill to a notice of intent to levy — respond at the earliest rung you're on.
A bill · decoded, with deadline countdown →
A bill · decoded, with deadline countdown →
A bill · decoded, with deadline countdown →
A bill · decoded, with deadline countdown →
A different code on your letter?
We only publish a decoder page once we’ve verified that notice’s mechanics against the IRS’s own pages — these six are what we cover today, and more are being verified. For any other code, the IRS’s official explanation is at irs.gov: Understanding your IRS notice or letter.