Some IRS letters are routine. Others start a deadline you cannot
get back. We translate the notice, identify what the IRS believes
happened and help you understand the next practical step without
tax jargon or scare tactics.
Select the notice or letter number below. If yours is not listed,
keep the complete letter and call us—the number and response date
will help identify the process.
1What notice is it?Find the CP or Letter
number—not just the balance.
2What is the deadline?Some dates preserve appeal
or Tax Court rights.
3Is the IRS correct?Compare the notice with the
return, transcript and source documents.
4What does the IRS want?Payment, documents,
identity verification and a signed agreement are not the same
response.
Balance due and collection
The notices become more serious as the sequence continues.
A balance-due letter does not mean the IRS will levy tomorrow. But
repeated notices show that the account is moving through collection
while penalties and interest continue.
CP14Action required
First balance-due notice
What it means
The IRS says you have unpaid tax and is sending its first bill
for that balance.
If ignored
Interest and the failure-to-pay penalty generally continue
until the balance is resolved.
Next step
Confirm the tax period, payments and amount. If it is correct,
address payment or the appropriate resolution path before
later collection notices arrive.
The IRS matches returns against Forms W-2, 1099, K-1 and other
third-party reports. Mismatches can result from omitted income—but
also duplication, reporting under the wrong taxpayer or income shown
elsewhere on the return.
CP11Deadline-sensitive
The IRS corrected the return
What it means
The IRS says it found one or more errors and changed the
amount you owe.
If ignored
If you disagree and do not contact the IRS by the stated date,
important reversal and appeal rights can be lost.
Next step
Compare the notice line by line with the filed return. Agree
only after confirming the IRS change is correct.
The IRS sees a possible difference between the return and
information from employers, banks, payment platforms or other
payers, and wants more information.
If ignored
An incomplete or unsupported response can lead to a proposed
adjustment.
Next step
Identify the exact W-2, 1099, K-1 or other item at issue and
respond with a clear reconciliation and supporting records.
Third-party information does not match the return, so the IRS
is proposing a tax increase or other adjustment.
If ignored
If you do not respond, the proposal can advance to a statutory
notice and eventually become an assessed balance.
Next step
Do not automatically agree or file an amended return. First
determine whether the income was omitted, reported elsewhere,
duplicated or belongs to someone else.
Some notices mean the IRS is verifying the return before releasing a
refund. The right response may be to wait, verify identity or
provide narrowly targeted documents.
CP05Review / wait
Refund under review
What it means
The IRS needs more time to verify income, withholding, credits
or business income.
If ignored
Your refund is delayed, but the notice does not by itself mean
you did anything wrong.
Next step
If you filed the return, the IRS generally says no action is
needed unless it contacts you or 60 days pass without an
update. If you did not file it, identity theft may be
involved.
These are the letters to put at the top of the pile.
When a notice opens Tax Court or collection-hearing rights, talking
with the IRS does not necessarily extend the filing deadline.
Calendar the date first.
CP3219A / Letter 3219Critical deadline
Statutory Notice of Deficiency
What it means
The IRS intends to assess proposed additional tax and is
formally notifying you of the right to petition the U.S. Tax
Court.
If ignored
The Tax Court filing deadline shown on the notice generally
cannot be extended. Sending documents to the IRS does not stop
that clock.
Next step
Calendar the petition deadline immediately. Evaluate the
proposed changes and decide whether to resolve them with the
IRS or protect Tax Court rights.
These letters involve a final levy warning or notice that a
federal tax lien was filed, together with rights to request a
Collection Due Process hearing.
If ignored
Missing the stated hearing deadline can reduce available
appeal protections while enforced collection continues.
Next step
Get the entire letter reviewed immediately. The detailed
lien-and-levy process will be covered on our separate page.
These notices can create obligations beyond paying a bill.
A payer may need to correct records, contact payees, begin backup
withholding or defend proposed per-return penalties.
CP2100 / CP2100ABusiness action
Name or TIN mismatch
What it means
A business or other payer filed information returns with
missing or incorrect taxpayer-identification numbers or
name/TIN combinations that do not match IRS records.
If ignored
The payer may need to send B Notices, solicit corrected
information and begin 24% backup withholding. The payer can be
liable for amounts it should have withheld.
Next step
Compare the IRS listing to business records, follow the First
or Second B Notice procedure and document every required
solicitation.
Identity-verification and missing-document letters can stop
processing even when the tax shown on the return is correct.
5071C / 4883CVerify securely
Identity verification
What it means
The IRS needs to confirm that you filed the return before it
will continue processing it.
If ignored
Ignoring the letter can delay the return or refund. If you did
not file the return, identity theft may be involved.
Next step
Use only the verification method and contact information shown
on IRS.gov or the letter. Never provide credentials to an
unsolicited caller, text or email.
Let’s identify the deadline before deciding what to do.
Give us 15 minutes to understand what the IRS sent. We will
explain how urgent it appears, what the IRS is asking for and
whether professional help may make sense.
This page provides general educational information, not legal or tax
advice. Always read the complete notice and use its actual response
date and instructions.
