On my 1099-NEC, which I imagine all are standard since it's a government form, it has the payer's name box. Under that box it says "payer's TIN". This number is either in EIN or SSN format depending on the payer's business structure. The box to the right of "Payer's TIN" is "Recipient's TIN" which is a bunch of x's followed by a 4 digit number.
If you don't have a number in the "Payer's TIN" box, you need to call the payer and get it.
