Sample Letter to Bank Informing the Death of the Account Holder. The death claim letter should be written in the formal letter format.A death claim letter format for bank is straightforward. Moreover, you just have to submit documents like a death certificate, ID proof, etc. To order a death certificate you will need: Name of the decedent; Date of death; City where the death occurred. I need to write to several organisations including banks, insurance and mortgager company to inform them of my partners death. This letter is from an executor notifying a bank about an account holder's death. If the addresses for any heirs or next of kin are unknown, the executor must post a notice in a newspaper that's available in the county.