In some instances, we require a proof of address to be certified. This is usually because you cannot be electronically verified at the address you have provided. To certify an address you can do one of the following:
Certification from a member of a professional accounting or legal body. This requires them to attest to the accuracy and true nature of the document. They must provide their professional body membership ID upon signature.
The Post Office in the UK provides document certification. You can view more information here.