If you would like to authorize someone to request bank statements on your behalf, here is a sample authorization letter to request bank statements.
The Bank Manager
[Name of Bank]
Subject: Authorization Letter For Collection Of Bank Statement
Please allow [Name of Entrusted Person] to collect my bank statement on my behalf. My account number is [Account Number], and I wish to collect my statement for the duration of [Date] to [Date].
[Name of Entrusted Person] is also authorized to sign any documents on my behalf.
Thank you for your help.