NEPA Community Federal Credit Union offers our members countless valuable services, one of which is our FREE Signature Guarantee program. This complimentary service is a written guarantee verifying that your signature is valid. Signature Guarantees must be made by either a domestic stock exchange or other acceptable guarantor. Notary publics are not authorized to make a signature guarantee, which is a common requirement when mailing an official document or certificate, or transferring, redeeming shares, or changing ownership of an account.