Short answer. Joint, by default. Article 1208 provides that where neither the law, the nature of the obligation nor its wording shows otherwise, the debt is presumed divided into as many shares as there are debtors, each share treated as distinct. Silence therefore favours the co-signer, not the lender.

What the law says

the credit or debt shall be presumed to be divided into as many shares as there are creditors or debtors, the credits or debts being considered distinct from one another

Civil Code, Article 1208 — Presumption of Joint Obligation. Read the full provision →

The default is division

Article 1208 states the rule in a single sentence: if from the law, or the nature or the wording of the obligation the contrary does not appear, the credit or debt shall be presumed to be divided into as many shares as there are creditors or debtors, the credits or debts being considered distinct from one another. Two signatories on a silent instrument therefore owe half each, and the halves are treated as separate debts rather than as two doors into the same one. The presumption operates in the co-signer's favour, which means the lender carries the burden of displacing it. You do not carry the burden of proving that your exposure is limited.

Three things can displace it

The presumption yields to the law, to the nature of the obligation, and to the wording — and in practice it is almost always the wording. A single line saying the signatories are jointly and severally or solidarily liable displaces the entire default. So the useful exercise is not to argue about presumptions but to read every page, including the dense text above the signature block and any promissory note, disclosure statement or continuing agreement the contract incorporates by reference. Standard bank and financing forms contain that line as a matter of course, and a borrower who remembers no such clause has often simply never been shown the second page.

What division actually gets you

Where the debt really is joint, the consequences run in the co-signer's direction. Each debtor's share is a distinct debt, so a creditor demanding the whole from you can be met with the answer that only your portion is demandable from you at all. Your co-signer's default does not enlarge your share, and his insolvency is the creditor's problem rather than yours to absorb. Paying your half discharges you even if the other half is never paid. The same logic runs on the creditor side of a joint credit: a creditor may demand only his own share and cannot collect the entire sum and account for it afterwards.

Do not confuse indivisibility with solidarity

This is the usual source of muddle. Article 1210 provides that the indivisibility of an obligation does not necessarily give rise to solidarity, nor does solidarity of itself imply indivisibility. An obligation can be impossible to perform in parts and still be joint. Article 1209 governs that case: where division is impossible the debt can be enforced only by proceeding against all the debtors, and if one of them is insolvent the others are not liable for his share. Money debts rarely raise the point, but a joint undertaking to deliver a specific thing or complete one indivisible work does.

Cases citing this provision

These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.

Related provisions

Note. Statute text quoted on this page is reproduced from the official enactment and is linked to the full provision. The explanation around it is general legal information from Vivas & Nobles Law Office, not legal advice. Whether it applies to your situation depends on facts only a lawyer reviewing them can assess.