What documentation do I need to open accounts for a Sole Proprietorship? Two forms of identification for each signer on the account Certificate of assumed business name Assignment of Tax ID/EIN or 1st two pages of recent tax return Have more questions? Submit a request 0 Comments Article is closed for comments. Related articles What documentation do I need to open accounts for a DBA? Mastercard debit card or Mastercard Credit Card was lost or stolen. Who should I call?