A person who appears to be a principal, whether by the terms of a written instrument or otherwise, may show that the person is in fact a surety except as against persons who have acted on the faith of the person's apparent character of principal.
Mont. Code Ann. § 28-11-402
When apparent principal may show surety
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.