When to use special power of attorney and when to use authorization letter

Dear Attorney,

I just want to be clarified when to use the special power of attorney and when authorization letter can suffice.

our resource speaker for a seminar had instructed our staff to claim his check payment for the services he rendered. the check was released by our office cashier and our resource speaker confirmed that it was received by him. now, our auditor is using this against us saying that the staff who was instructed to claim the salary does not have a special power of attorney.

in my years in this company, i know that authorization letter is enough for the cashier to release checks to the person given authority.

we would really appreciate a prompt reply on this matter. thank you so much.

i think nowadays and according to experience, if it involves money, authorization letter is not enough so SPA should be used.

i have a question also,Hi i recently sent a special power of attorney to my son in the philippines to sell/buy a land. Does he still need my identification when doing all the transaction? Since he is acting on my behalf, wouldn't it be legit if my son shows his ID instead? thank you.