Formal:
* Kasamang nagpipirma (Co-signer): This translates literally to "co-signer" and is the most accurate formal term.
* Kasamang tagapag-utang (Joint debtor): This means "joint debtor" and emphasizes the shared responsibility for the debt.
Informal:
* Katulong sa pagbabayad (Helper in paying): This means "helper in paying" and is more informal but still conveys the meaning of a comaker.
* Nakikipag-utang (Borrower): This is a more general term for someone borrowing money, but it can also refer to a comaker if the context is clear.
Ultimately, the best term to use depends on the specific situation and your intended audience.