The VA only recognizes accredited representatives. Everyone else is legally barred from representing you, no matter what their ad says.
The VA does not let just anyone represent a veteran. Under 38 CFR § 14.629, only accredited attorneys, accredited claims agents, and recognized Veterans Service Organization representatives are authorized to prepare, present, and prosecute claims. Everyone else is operating outside the law.
The "coaching" loophole
A wave of unaccredited "claim consultants" and "coaches" charge large fees to tell you what to write while carefully never signing anything. They do this because they legally cannot represent you, and because it lets them dodge the fee rules that protect veterans.
How to protect yourself
Ask for the accreditation number and verify it on the VA's public accreditation search. An accredited agent's fees are regulated; a coach's are not. I am VA-Accredited Claims Agent #45147, and that accountability is the entire point.
Your claim file is too important to hand to someone who cannot legally stand behind it.
Every VA disability claim is adjudicated under the procedures in M21-1, the VA's internal Adjudication Procedures Manual, and the regulatory standards in 38 CFR Parts 3 and 4. Raters are bound by these rules, and when they deviate, veterans have grounds to challenge the decision. Under Gilbert v. Derwinski, the benefit-of-the-doubt standard at §3.102 requires the VA to resolve every evidentiary tie in the veteran's favor. Under Esteban v. Brown, separate disabilities producing separate functional losses must be rated independently, even when they arise from the same injury, the VA cannot collapse distinct impairments into one rating.