If the account is titled:

Estate of John Doe

Does it have to have an EIN#?

yes, a SSN dies with you, so an estate account must have it's own tax ID#.

You need to be careful about what type of "estate" account is involved.

Probate estates clearly require the use of an EIN.

In some states, conservatorship and guardianship proceedings are also referred to as the "Estate of _______". For these types of estates you would use the conservatee/ward's SSN because the person who is the subject of the court proceeding is still alive.

Just to make this a duet, the reference to "estate" is a reference to property, not death. Ray's right, a financial guardian is as responsible for an "estate" just as a personal represenative is responsible for an "estate."

In an effort to maximize the IRS' chances of hitting the appropriate name/TIN combination, I suggest you use "John Brown Estate, Jane Blue, Personal Representative." (Put the name at the beginning of the account.) It's the fiduciary title that is your clue to the situation and the correct TIN.

And the last chorus: A decdent's estate has an EIN. A guardianship estate should use the SSN of the person under the disability.

Also, you need to make sure that you understand how to establish accounts on your system to insure the appropriate IRS control name or you can have serious TIN mismatch issues. On JHA, you have to override the IRS control name field or it will be ESTA instead of BROW (referencing Ken's example).