A short one, learned the hard way.

I had an LOA that listed a service address and both accounts serving it. Perfectly reasonable on its face. The problem surfaced later when we went after a sales tax exemption that applied to only one of the two meters. Because the authorization was framed around the premises rather than the account, there was a real argument that anything filed under it swept in the meter that did not qualify.

Two related points on the same document.

Signing capacity is the single most common reason a utility bounces an LOA. Most templates carry a line reading "Signature/Title" and most signers write their name and stop. If the customer of record is a corporate entity, the utility wants to see that the human signing holds authority to bind it. Put "Title / capacity" on its own labeled line and people fill it in.

Also check that your template does not name two different firms. I have seen more than one where the grant runs to one company and the revocation clause names another, because somebody built it by editing an older document. It is a small thing until a utility rep decides to be difficult about it.

If two related entities hold accounts at one address, get an attestation of the relationship on the same page as the signature. You will need it later for any combined-service question and it saves a round trip.