On the whole, promissory notes are governed by the laws where they are entered into. In most cases, this is the same jurisdiction where the lender, not the borrower, resides. In case the note touches on the purchase of some assets, the jurisdiction chosen is that of the place where the asset is located. In case the parties to the agreement are from different states, the state law applicable should be expressly stated in the document to ward off any ambiguities.