The local Social Security hearing offices have had an uptick in requests for information regarding a person's Social Security information from attorneys before a disability claim has even been filed.
The correct form in these circumstances is the Consent to Release Information, form SSA-3288 (link opens a PDF of the form) rather than the usual Appointment of Representative form 1696, which is appropriate for representatives to submit to the SSA after a disability or SSI claim has been filed.
I have been told that the local offices are going to start insisting on receiving form 3288 before information is released. So, get your client (or prospective client) to complete one if a claim has not yet been filed. A copy of the signed form, rather than the original, is fine.