I Got a Letter From the IRS — Now What?
By Forrest Baumhover, CFP®, EA · Last verified August 28, 2026
A letter from the IRS showed up in your mailbox, and before you open it — or right after — you want to know how worried to be. This page walks through the two questions that matter most and points you to the right next page for your specific letter.
Question 1: Is It a Bill, or a Question?
Look for a dollar amount near the top of the letter, next to a due date. If there's a number and a due date, the IRS is either billing you or proposing a change to your return. CP14 is a common example of a bill — it's tax you already owe. CP2000 is a common example of a proposed change — it's based on income the IRS thinks you didn't report, and it isn't final until you've had a chance to respond. If there's no dollar amount at all, and instead the letter asks you to confirm your identity, send documents, or explain something, it's a request, not a bill. Nothing is owed unless (and until) it turns into one.
This distinction changes everything about what to do next. A bill or a proposed change has a real deadline. Miss it, and interest and penalties keep adding up — or, for the most serious letters, you lose your right to dispute the amount at all. A request — like the four identity-verification letters below — works differently: taking a few weeks to respond doesn't add any interest charges, but it does hold your return and any refund until you respond.
Question 2: What Does the Number on the Letter Actually Mean?
Every IRS notice and letter has a code printed on it, usually in the top or bottom corner — something like CP14, CP2000, LT11, or Letter 5071C. That code is the fastest way to find out exactly what a letter wants and what to do about it — not the letter's tone, length, or how urgent it sounds.
Look up your letter's exact code in the full library — every notice and letter we cover has its own page with what it means, your deadline, and exactly what to do.
Search the IRS Notice Library →One Common Example: Identity Verification Letters
If your letter's code is 5071C, 4883C, 5747C, or 6330C, the IRS isn't billing you or examining your return — it's asking you to prove that you're really the person who filed it. Between the four letters, there are three ways to do that — online, phone, or in person — and we've written a page for each with the exact steps:
Letter 5071C — verify online or by phone, your choice. Letter 4883C — phone only. Letter 5747C — requires an in-person visit. Letter 6330C — a limited pilot letter, works exactly like 4883C.
If any of those phone lines are giving you trouble, see How to Actually Reach the IRS for realistic wait times and which number is actually yours to call.
Common Questions
I can't find a code on my letter. What now?
Check the top-right corner and the bottom of the last page — that's where the IRS prints it on nearly every notice and letter. If you truly can't find one, search the IRS Notice Library by keyword instead of code; most pages there are also searchable by what the letter is about.
Do I need to respond right away?
It depends on the letter. A bill for tax you already owe, like CP14, usually asks for payment within about three weeks to stop interest from adding up — but missing that date doesn't trigger anything drastic on its own. A proposed change, like CP2000, gives you 30 days to respond before the IRS moves forward with it. The most serious kind — a Statutory Notice of Deficiency, sometimes called a 90-day letter — gives you a strict 90 days to take the IRS to Tax Court if you disagree, and no one can extend that deadline. A request, like an identity-verification letter, doesn't carry a penalty for taking a few weeks, but your return and refund stay on hold the entire time you wait, so responding sooner gets you your refund sooner.
Is this letter a scam?
A real IRS letter always has a notice or letter number, and the IRS never first contacts you by email, text, or social media to ask for personal or financial information. If you're unsure, look up the exact code from your letter in the IRS Notice Library rather than clicking any link the letter itself provides.