Short answer. Article 1369 does not set its own procedure, it hands that job to the Supreme Court's rules of court. Practically, a reformation case is filed as an ordinary civil action for reformation of instrument in the proper trial court, following the regular rules on complaints, evidence, and trial, since no separate special procedure was ever promulgated for it alone.
What the law says
The procedure for the reformation of instrument shall be governed by rules of court to be promulgated by the Supreme Court.
Civil Code, Article 1369 — Procedure for Reformation. Read the full provision →
A Deliberate Gap
Articles 1359 through 1368 spell out when an instrument may be reformed and who may ask for it, but Article 1369 leaves the how to the Supreme Court's rule-making power rather than freezing a fixed procedure into the Civil Code itself. That design choice keeps the mechanics flexible as the Rules of Court are revised over the decades. This mirrors how the Code generally treats matters of pure procedure, leaving the details to whichever body has the constitutional authority to prescribe how the courts operate, rather than locking a step-by-step process into a substantive law that would be harder to amend.
What Filing Looks Like in Practice
Because no distinct special procedure was ever issued just for reformation, a claimant files it as an ordinary civil action, a verified complaint naming the parties, describing the true agreement, the erroneous instrument, and the ground for reformation, whether mutual mistake, fraud, inequitable conduct, or accident, and praying that the court order the instrument corrected to reflect the real intent of the parties. The complaint typically attaches or quotes the disputed instrument itself, so the court can compare the document as written against the agreement the plaintiff claims was actually intended.
Same Court, Ordinary Rules
The case then proceeds through the regular stages of a civil suit: summons, answer, pre-trial, and trial, where the claimant must prove both the true agreement and the discrepancy in the written instrument by clear and convincing evidence. There is no shortcut docket or summary process reserved for reformation cases alone. Because the standard of proof is demanding, the outcome often turns heavily on documentary evidence, correspondence, or witness testimony that predates or surrounds the signing of the instrument.
Combining It With Other Claims
Because reformation shares an ordinary procedural track with other civil claims, it can be joined with related causes of action, such as specific performance or damages, in a single complaint rather than requiring a separate proceeding, so long as the usual joinder rules on jurisdiction and venue are respected. Failing to join a related claim does not bar it forever, but a party who wants full relief in one proceeding, rather than two separate lawsuits over the same transaction, should raise every related cause of action at the outset.
What to Budget For
For a party planning to file, this practically means budgeting for a full-length civil case rather than a quick motion: pleadings, discovery of the surrounding circumstances, and a trial on the merits, since the reformation claim stands or falls on evidence just like any other cause of action. Settlement is also possible at any stage, since reformation cases, like most civil disputes, can end in a compromise that corrects the instrument without a full trial.
Related provisions
- Civil Code, Article 1369 — Procedure for Reformation
- Civil Code, Article 1359 — Reformation of Instruments