Written Agreements

Usually yes it is valid. A simple agreement written on a napkin can be so long as both parties have signed it. Now there could be exceptions due to how it was written, some laws could invalidate it or the age of the agreement. It is best to check with a lawyer so you know for sure.

You better be checking with your local authorities. In some areas that could be binding. If you enetered into something that you actually signed something then it would be good of you to complete the agreement. Your word is even more important. Good luck with this.

In most cases, if it is signed by both parties and each one agrees that it was signed by both parties, there will be no question about its validity. I have seen verbal agreements stand up in court, so a signed document, whether notorized or not, would hold up as long as the other party does not dispute signing it. If there is a dispute with the signature, you can always request a handwriting analysis, though you would have to pay for it.