A DDA debit refers to a direct debit authorization, which is an authorized withdrawal from an individuals bank account by a third party. DDA accounts, on the other hand, are a type of bank account that offers access to your money without requiring advance notice. Money can be withdrawn from a DDA on demand and as needed, and these accounts can allow for different types of transactions. For example, a DDA deposit is a transaction in which money is added to a demand deposit account, while a demand deposit debit is a transaction in which money is taken out of the account. Checking accounts, share draft accounts, savings accounts, and money market accounts are all examples of demand deposit accounts. The term DDA can also refer to direct debit authorization, direct debit mandate, or ACH authorization, depending on the jurisdiction.