Received an IRS Letter? Start With the Code.
Find the notice number, understand whether the IRS is proposing, billing, or collecting, and protect the response date before options disappear.
A guide by Taxstra Tax & Accounting — CPA-led tax strategy for business owners
Written by Bryan Martin, CPA, Managing Partner and Founder of Taxstra. Last updated July 10, 2026.
Find the code
Look for CP, LT, or a letter number on the first page.
Mark the date
Use the exact response or petition date printed on the letter.
Reconcile first
Compare the notice with your return, payments, and IRS records.
Find Your IRS Notice
Choose the description that matches the letter in your hand
The IRS proposes a change
Start by testing the IRS calculation against your return and source documents.
The IRS says a return or payment is missing
Reconcile the IRS account before filing or paying a second time.
Collection is escalating
These letters can affect an existing payment arrangement or precede enforced collection.
Three Rules for Any IRS Letter
Do not ignore it
Silence can turn a proposed adjustment into an assessment or allow a collection case to progress.
Do not pay it blind
Confirm the IRS used the right income, basis, payments, taxpayer, and tax year before treating the amount as final.
Do not use a generic deadline
The notice in your hand controls. Different codes create different procedures, and the mailing date may be earlier than the day you opened it.
When to hand the letter to a professional
- The amount is material or the calculation involves stock, crypto, a business, rentals, or multiple states.
- The letter mentions levy, lien, a defaulted payment plan, a hearing, or U.S. Tax Court.
- You already responded and the IRS did not resolve the issue.
- Several tax years or unfiled returns are involved.
- You want an authorized representative to obtain records and handle contact.
Send Taxstra the Letter, Not a Guess
We can identify the notice, reconcile the IRS position, track the response date, and tell you what a defensible next step looks like.
Find Out What You're Overpaying in Taxes
Book a free 30-minute call to walk through your situation. We'll tell you exactly how our CPA-led team can help — and whether we're the right fit.