The LTR 170C is a payment acknowledgment. The IRS received a payment from you and is confirming it was applied to your account. This is primarily administrative — the IRS documenting that your money was received and credited.
Verify the Details
Confirm the payment amount matches what you sent, the payment was applied to the correct tax year and tax type, and the remaining balance (if shown) reflects the payment. If any of these are wrong, contact the IRS with your payment records.
Keep This Notice
The LTR 170C serves as the IRS's receipt for your payment. File it with your tax records for the relevant year. If there's ever a dispute about whether you made the payment, this notice plus your bank records or cancelled check create a complete paper trail.
Don't Assume It's Resolved
A payment acknowledgment doesn't mean your account is fully resolved. If the payment was a partial payment, the remaining balance continues to accrue interest and penalties. If the payment was supposed to settle the account in full, verify that no remaining balance exists by checking your IRS Online Account or requesting an account transcript.
If something doesn't look right on your LTR 170C, call us at (813) 229-7100.