Short answer. As a general rule, yes. Rule 3 of the Rules of Court states that husband and wife shall sue or be sued jointly, except as provided by law. Joinder is the default for married litigants; a spouse sues or defends alone only where some law carves out an exception.
What the law says
Husband and wife shall sue or be sued jointly, except as provided by law.
Rule 3, Section 4 — Spouses as parties. Read the full provision →
A short rule with a long reach
The provision is one sentence: husband and wife shall sue or be sued jointly, except as provided by law. The command is mandatory in form — shall — and it works in both directions. A married person bringing a civil action is expected to join their spouse as co-plaintiff, and a person suing a married defendant is expected to implead both spouses. The rule reflects how marriage organises property and liability: because most of what married couples own and owe is held in common, a judgment touching one spouse's interests will usually touch the other's.
Why the law wants both spouses in the case
A lawsuit binds only its parties. If property of the marriage could be litigated with only one spouse in the case, the absent spouse could later attack the result as one reached without them — and the winning party's victory would stand on sand. Requiring the spouses to litigate jointly puts everyone whose interest is at stake before the court in one proceeding, so the judgment settles the matter once. For a plaintiff, this is not a technicality: suing only one spouse over an obligation or property involving the marriage invites objections about who ought to have been made a party.
The exception clause does real work
The rule closes with except as provided by law, and that clause is not decorative. Philippine law recognises situations in which a spouse properly litigates alone — most obviously suits between the spouses themselves, and matters that concern one spouse's exclusive property or purely personal rights. Which side of the line a given case falls on depends on the parties' property regime and on the statutes governing the specific claim, which is precisely the kind of question to put to counsel before filing rather than after an objection is raised.
What to settle before the case starts
Whether you are suing or being sued, start with two facts: what property regime governs the marriage, and whose right or obligation the case actually concerns. A claim over conjugal or community property points firmly toward joinder; a claim strictly personal to one spouse may not. If you have been sued without your spouse — or sued only one member of a married couple — raise the party question with counsel early. Defects in who has been joined are far cheaper to fix at the pleading stage than after judgment.