Can I allow both ACH and credit card payments?
Yes. You can set a limit for the maximum amount you're willing to accept via credit card. This can be useful to limit your exposure to credit card fees. For invoices greater than the limit ACH payments will be the only option available to your customers.
You can also add a surcharge for credit card payments to help offset the fees.
If you already use Stripe for credit card processing receivabl.es is a great drop-in replacement.