Send only the fields you want to change: omit a field to leave it unchanged, or set a nullable field (thresholds, auto_decline_categories, amount caps) to null to reset it to the platform default. auto_decline_on_sanctions is a plain boolean with no separate default, so send it explicitly to change it — null is a no-op, not a reset.

{ "review_threshold": 50, "amount_decline_cap": "20000" }

The example above tightens the review threshold and adds a decline cap while leaving every other field (including decline_threshold) at its current value.

Validation

• decline_threshold must be >= review_threshold.
• amount_decline_cap must be >= amount_review_cap.

Both are checked against the effective value (what you're changing to, or the current/default value for anything you omit) — so a partial update that would invert either band is rejected rather than silently making a tier unreachable.

Errors