IRS NOTICE REFERENCE
Letter 105 C
Factual reference for Letter 105-C. General information only — not legal or tax advice.
General information only. Not legal or tax advice.
Notice details
- Notice code
- Letter 105-C
- Category
- Refund claims and litigation
- Severity tier
- Tier 4 — Escalation warranted. The notice involves collection enforcement, appeals rights, or significant penalty exposure.
- Governing law
- §6532; §7422; §6511 (Internal Revenue Code sections)
- Escalation flag
- This notice carries a forfeitable right, a hard statutory deadline, or criminal-preparer risk. It is flagged for escalation in the TaxRiskOS workflow.
- Source
- IRS Taxpayer Advocate Service
What the IRS says to do
The following are your options: Agree with the IRS for the reasons stated in the letter – do nothing. Don’t agree – Reply back to the IRS area which issued the letter stating why you don’t agree, P rovide whatever documents are needed to support your explanation and direct the IRS to send your request to the Independent Office of Appeals if they decide not to all ow the claim. The IRS should consider your explanation before forwarding your request to the IRS Independent Office of Appeals (Appeals) which will decide if the claim should be allowed. When creating your explanation be sure to follow Publication 5 for how to word your request to to go to Appeals. If you don’t agree with the IRS’s
This is the IRS’s own guidance reproduced from the IRS notice page. It describes the IRS’s process — it is not legal or tax advice from TaxRiskOS.
Governing IRS procedure (Internal Revenue Manual)
The IRS’s own internal procedures for handling this notice type are documented in the Internal Revenue Manual:
- IRM 4.10.11 — 4.10.11 Claims for Refund, Requests for Abatement, and Audit Reconsiderations
- IRM 4.19.16 — 4.19.16 Claims
Reference to published IRS procedure. General information — not legal or tax advice.
Official IRS reference
Read the official notice page on IRS.gov: https://www.taxpayeradvocate.irs.gov/notices/letter-105-c/
Related tools
TaxRiskOS is workflow software for practitioners — it captures the notice, computes the deadline, surfaces the escalation tier, and builds a document checklist. It documents process; it does not give advice or draft responses.
Check this notice’s deadline (free tool)