Who do I contact if I have a concern or question associated with my EFIN?

Contact the e-help desk at 866-255-0654 (6:30 a.m. to 6 p.m. CT) to find out additional information or visit Information for IRS e-file Providers on IRS.gov if you have questions or concerns in regards to your EFIN. 

 Also from IRS note number 6: 

Once you have completed the EFIN application process and received your EFIN, it is important that you keep your account up-to-date at all times. This includes:

1. Review your e-file application periodically. Your e-file application must be updated within 30days of any changes such as individuals involved, addresses or telephone numbers. Failure to do so may result in the inactivation of your EFIN.
2. Ensure proper individuals are identified on the application, and update as necessary. The principal listed on the application is the individual authorized to act for the business in any legal or tax matters. Periodically accessing your account.
3. Adding any new principals or responsible officials
4. Updating any business address changes, including the adding new locations.
5. Your EFIN is not transferable; if you sell your businesses, the new principals must obtain their own EFIN
6. There must be an EFIN application for each office location; if you expand your business, an application is required for each location where e-file transmissions will occur.