A surety cannot be held beyond the express terms of the surety's contract, and if the contract prescribes a penalty for breach, the surety cannot in any case be liable for more than the penalty.
Mont. Code Ann. § 28-11-411
Extent of surety's liability
En
Official source: Montana Code Annotated (Montana Legislature). Reproduced from public-domain Montana statutes; confirm against the official source for the current text. Not legal advice.