When I got Power Of Attorney for a friend who was in ill health, I thought that the POA document, which was signed when he was lucid, would let me represent him in all financial matters if he ceased to be lucid. It turns out the IRS doesn't automatically recognize POA documents as allowing a person to handle another person's tax matters.
As usual, different IRS people have different ideas of what I should do. Whoever (or whatever computer) sends out the IRS mail thinks I should fill out form 2848 "Power of Attorney and Declaration of Representative". However, I don't fit into any category listed on that form. I have no special certification, as required by some categories, and I am not a family member. One local IRS person was willing to speak to me when I presented my POA document. Later, a different IRS person said she couldn't discuss my friends taxes. She said that instead of form 2848, I should present her with form 8821 "Tax Information Authorization".
It makes sense to me that form 8821 is the correct form. However, both form 2848 and form 8821 require the signature of the taxpayer and my friend is currently both too weak to write a signature and also not lucid. I'm wondering if the POA document gives me the authority to sign form 8821 as the taxpayer and thus authorize myself to represent my friend.
The problem is not particularly urgent, because my friends problem with the IRS is that it refuses to process his return because it says he is deceased. If the IRS did process his return, it would only mean a small refund for him.