We received notice from a supplier stating that my contractor did not pay them and they intend to file a lien. However... 1. It's a homestead, no contract was filed with the county, both spouses did not sign 2. The notice is a month late and not in the proper format with the residential code portion in it Would this supplier still be able to file a lien if I ignore their letter? Or should I inform them about filing an invalid lien?
A subcontractor or supplier who dealt with the general contractor does not need a direct contract with owner to file a lien even for a homestead. That requirement for the general contractor. However, a subcontractor or a supplier does need to provide a preliminary notice to both the owner and the general. That notice3 must be provided no later than the 15th of the second month following the performance of work or supplying materials. I don't know how you are calculating when you say a month late. If it is even a few days later than the deadline described above, then the lien is not valid. Best approach is to contact the supplier and notify them that such a lien is not valid. If the supplier refuses to remove the lien, you can have a cause of action against the supplier to remove the lien and perhaps even a claim of fraudulent lien which can expose the supplier to damages and attorney fees.
They can always file a lien, but based on the information you have provided, the lien would be improper and subject the contractor to potentially severe liability.