Hi Cynthia,
I know this post is from a while ago, but I thought I’d answer anyway!
It depends on the client. Most of mine are fine with a signed statement certifying my qualifications and the accuracy of the translation (to the best of my ability). Some require a Notary’s signature as well, it just depends on the client. My default is the signed statement, but if they want a Notary, I can do that too.
Holly