Claim filed too late
The IRS may determine the claim was filed after the applicable refund-claim deadline.
IRS Letter 105C • Refund Claim Disallowed
Received IRS Letter 105C?
Letter 105C is the IRS’s legal notice that it fully disallowed a claim for credit or refund. It states the reason for the decision and the affected tax period.
The two-year period matters. Requesting reconsideration or Appeals review does not extend the time to file a refund suit.
There is no fee to book the call. No documents are required when booking. Have every page of Letter 105C and the refund claim available during your call.
Sonya D. Bright, EABaytown-BasedVirtual Nationwide Service
What Letter 105C Means
The IRS denied the requested refund or credit
The disallowance may be based on timeliness, limits on the refundable amount, eligibility, substantiation, or another reason stated in the letter.
Letter 105C generally covers a full disallowance. A partial disallowance is commonly issued on Letter 106C.
Why It Was Sent
Common reasons a claim is disallowed
Refund amount limited
Even a timely claim may be limited by the amount paid within the applicable lookback period.
Eligibility not established
The IRS may conclude the taxpayer did not meet the legal requirements for the credit or refund.
Records were insufficient
The submitted documents may not establish the facts or amount claimed.
Computation disputed
The IRS may disagree with how the overpayment, credit, penalty abatement, or refund was calculated.
ERC disallowance
Businesses may receive Letter 105C when the IRS fully disallows an Employee Retention Credit claim.
Response Choices
Choose the path that protects the claim
If you agree
No response is generally required, but retain the letter and deadline calculation.
If you disagree
Respond to the issuing office with a clear explanation and documents supporting eligibility, timeliness, and the claim amount.
If you request Appeals
Ask that the claim be sent to the IRS Independent Office of Appeals if the issuing office does not allow it. Follow Publication 5.
Records To Review
Have these available for the call
- Every page of Letter 105C
- The refund claim and amended return
- Original return and filing proof
- Proof of tax-payment dates and amounts
- Records supporting eligibility and claim amount
- Earlier IRS correspondence and submission proof
Critical Deadline
Administrative review does not stop the refund-suit clock
Refund suit
A taxpayer may file in the United States District Court with jurisdiction or the United States Court of Federal Claims. Legal advice may be required.
Written extension
The IRS and taxpayer may extend the period using Form 907, but the agreement is not effective unless both parties sign it before the existing period expires.
Frequently Asked Questions
IRS Letter 105C questions
Is Letter 105C a tax bill?
No. It disallows a claim for credit or refund. It may affect an expected refund or account credit.
Can the IRS reconsider the claim?
Possibly. Submit a clear explanation and supporting records, but continue tracking the two-year deadline.
Does Appeals extend the deadline?
No. The period continues while Appeals considers the case.
What if less than six months remain?
Promptly evaluate whether a refund suit or a valid written extension is needed to protect the claim.
Is there a fee to book?
No. There is no fee to book the call. Professional work requires a separate written engagement.
Can TaxDecoders help?
Assistance may be offered after the letter, claim, payment dates, supporting records, and remaining deadline are reviewed.
Verified Resources
Official information
This page was reviewed on July 28, 2026. Always follow the dates and instructions printed on your actual letter.
Letter 105C roadmap
Refund claims
Appeal rights
Do not lose the Letter 105C two-year deadline.
Book a call with TaxDecoders. Have the complete letter, refund claim, payment dates, and supporting records available during the call.
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