What to do when a contractor threatens a mechanic lien on our house

Sounds immensely frsutrating, but at the end of the day, I don't see that you have any specific right to pay by credit card. While paying by credit card has become almost universal for every imaginable product and service, one does not need to affirmatively state they do not accept credit cards before the service is provided - the age-old adage of caveat emptor (buyer beware) is applicable here.

Depending on how much the principal payment is, maybe you just want to increase it by 2% or so to cover his credit card fees? Or maybe have him do a little more work somewhere else in the house so that while he will lose something on the fees, he will "gain" the additional work to off-set it?

Good luck!

Is there a written contract? If so, what does the contract say? Does it mention that payment must be made via cash or check? The simplest solution is oftentimes the best one: Just pay via cash or check. If you're truly adamant about using a credit card for whatever reason (maybe you earn rewards/miles), you may offer to pay his charge fees. This doesn't seem like something worth taking legal action over. You would likely spend more in legal fees than you would just paying your contractor's charge fees. In the future, you may offer to buy the materials for a home renovation project if you are looking to rack up credit card rewards.