Let's say  a business is accepting ACH payments for your gym membership. You debit 400 people on the 1st of the month and are funded $16,000. The gym has been struggling and on the 5th of the month shuts its doors and the owners skip town. The gym members have paid for a service they won't receive. If they go to their bank and revoke their authorization their bank can "force" a n electronic return of their money. If the processor can't get it from the gym owner who skipped town guess who pays?

That's why virtually any processor will get application information that serves to mitigate their risk. Typically you will be asked to show bank statements, Articles of Incorporation and possibly a tax return.