Thank you for the comment!!

I actually just checked in with Stripe because that sounded awesome! They say that the funds that customers put in via ACH are not able to be drawn upon for up to 5 days, until the transaction "succeeds".

We are slightly worried about using a credit card / line of credit as a buffer to that 5 day ACH, as it would be super risky as we could easily blow past a $100K credit line in the few days ACH would take to settle, leaving us high and dry.

If customers were to "pre-fill" accounts, that would allow for some really cheap funds, though :O Thank you so much for that tip!