The most common ACH Authorization is an authorization form that the customer signs. Sample ACH Authorization forms are included with RTO Pro.
You can also get a phone authorization from the customer, but for this type the authorization should be voice recorded or you should email the customer an authorization form and have them email you back that they authorize you to make the ACH debit.
Web authorization is when the customer gives you their bank account info and authorization through a website.
For more information about ACH Payments or proper ACH Authorization contact Profituity at (888) 436-5101 Ext. 21.