Is this a 1099-MISC that you received? If so, the Payer is the person/institution that sent you the form. So for a received 1099-MISC, a Payer's TIN is their Federal tax ID number.
If the 1099-MISC was sent to you, then you are the recipient or payee.
TIN is a generic term that encompasses many types of taxpayer ID numbers. Here's more info on TINs:
