The two service providers I would recommend are:
Both would be willing to work with you on customized rates (provided you have the volume to show for). Both are reasonably economical. Settlement times is usually 5 days, but if you have the volumes, you can negotiate it down 2 day or 3 days.
Both offer an API and recurring billing.
- ACHq - www.achq.com
- National ACH - www.nationalach.com
Both would be willing to work with you on customized rates (provided you have the volume to show for). Both are reasonably economical. Settlement times is usually 5 days, but if you have the volumes, you can negotiate it down 2 day or 3 days.
Both offer an API and recurring billing.