Enclose a copy of your voided check or pre-printed savings deposit slip with banking numbers printed on the bottom. Formats and Samples of Writing an Authorisation Letter to Collect Documents.Check how to write an authorization letter to collect documents. Go through the format and samples to write a well-structured letter to Bank Learn how to write an effective authorization letter for a bank statement to simplify your banking needs. Tips and examples included! This dynamic PDF is not fillable if you open it in your internet browser. Please use these steps to download, save, and fill out the form. For example, are you a joint owner of the account? Download forms to your computer before completing themInteractive PDFs must be saved to your computer to work properly.