CP 575 and 147C: the two letters that prove your EIN, and how to get the second one

The CP 575 is the notice the IRS generates when it assigns an EIN. It shows the company's name and address, the EIN, and the returns the IRS expects the company to file. It's posted once, to the mailing address on Form SS-4, and the IRS doesn't reissue it. Scan it the day it arrives and keep the original. If it's posted to us, it goes straight into your documents.

A 147C letter is the IRS's confirmation of an existing EIN, issued on request. It shows the same key facts and is accepted almost everywhere the CP 575 is. You request it by phone: the Business and Specialty Tax Line, 800-829-4933, from 7 a.m. to 7 p.m. local time inside the US, or the international line, 267-941-1099, from abroad. The caller has to be the responsible party or someone authorised on Form 2848 or 8821, and answers identity questions about the company. The IRS can fax the letter while you're on the call, if you have a fax number to give, or post it, which takes longer, especially abroad.

• The CP 575, scanned, almost always.
• A 147C letter, in the same way.
• Not a number typed into a form, a screenshot of an email, or a letter from your filing agent. The proof has to come from the IRS.

If the CP 575 misspells the company's name or shows the wrong entity type, the responsible party writes to the IRS explaining the error and asking for the record to be corrected, with the state's stamped articles attached. It takes weeks. A 147C issued after the correction shows the corrected record, and that's the letter to give the bank.

The IRS writes to the address it has on record, which is the one from Form SS-4 until you change it. If the company's mailing address changes, the next notice still goes to the old one unless you tell the IRS. Form 8822-B updates the address and the responsible party. It's sent by post and takes several weeks to process, and a change of responsible party has to be reported within 60 days.