What Letters 6509C, 6510C, 6526C is
Letters from the e-file help desk about an IR Application for TCC: 6509C and 6526C when an application has sat in Resubmission Required for 45 days (it is deleted at 90), and 6510C for non-use, sent before a TCC that has not been used for two years is dropped (IRM 3.42.9.22.1).
The deadline
Act before the 90-day deletion or the dormancy drop; the letter states the date.
What to do
Log in as a Responsible Official, complete or resubmit the application, or transmit a file to keep the TCC active. A dropped TCC means a new application with a processing clock measured in weeks.
The TCC and the IR Application
A Transmitter Control Code is the five-character credential that identifies a filer or service provider to the IRS's information return systems, FIRE and IRIS. It is obtained through the IR Application for TCC on IRS.gov, which requires at least one Responsible Official who verifies their identity through the IRS's sign-in service, names the forms the applicant will transmit, and is approved after a processing period of several weeks. Since FIRE's retirement for new filers and the move to IRIS, a payer that files its own returns needs an IRIS TCC, and a payer that uses a service provider files under the provider's. The application is a living record: an application left in Resubmission Required status (something was missing or a Responsible Official did not complete identity verification) is deleted after 90 days, and a TCC that has not been used to transmit anything for two years is dropped as dormant. The letters in this family are the warnings before each of those happens.
Keeping the credential alive
On a 6509C or 6526C, a Responsible Official signs in to the IR Application, completes whatever is flagged, and resubmits before the 90-day mark; a deleted application means starting over with a new processing clock, which during January can mean missing the filing deadline. On a 6510C, the fix is to use the TCC: transmit a file, even a test file where the system allows one, before the stated date. Payers who file through a provider sometimes hold their own TCC from an earlier year as a backup and are surprised to lose it; if you want to keep it, put an annual test transmission on the compliance calendar. Keep the Responsible Official list current as staff change, because an application whose only Responsible Official has left the company cannot be updated by anyone else without a new verification. The TCC lifecycle guide covers the application, roles and the FIRE to IRIS transition in detail.
Questions about Letters 6509C, 6510C, 6526C
Who receives Letters 6509C, 6510C, 6526C?
Transmitter. Letters from the e-file help desk about an IR Application for TCC: 6509C and 6526C when an application has sat in Resubmission Required for 45 days (it is deleted at 90), and 6510C for non-use, sent before a TCC that…
What is the deadline on Letters 6509C, 6510C, 6526C?
Act before the 90-day deletion or the dormancy drop; the letter states the date.
What should I do when Letters 6509C, 6510C, 6526C arrives?
Log in as a Responsible Official, complete or resubmit the application, or transmit a file to keep the TCC active. A dropped TCC means a new application with a processing clock measured in weeks.
Is Letters 6509C, 6510C, 6526C about my own income tax?
No. This decoder covers information reporting and withholding: the notices a payer, filer or payee sees because of Forms 1099, W-2, 945 and the TINs on them. Individual income-tax notices follow a different track.
Have a different notice? The IRS notice decoder lists all 77 in the order they tend to arrive.