Which box specifically? There is no such box labeled "account number" on a 1099-R form.
It is a 1099-R for my pension. It is formatted a bit differently than the other two 1099-R's I have. This box is in the lower left hand corner. Directly to the right is box 11 - '1st year of desig. Roth contrib'. Does that help?
The 1099-R interview only asks for the FEIN (federal tax ID number) of the brokerage or account trustee. This is always 9 digits only.
Whatever your personal account number is at the brokerage, it does not go in the 1099-R interview in turbotax and is not the same as the FEIN. Check your 1099-R carefully.
If you are importing a 1099-R from a brokerage online, and turbotax is creating this error, the import may be wrong, please let us know.