From a consumer perspective, paying via ACH is much more dangerous compared to paying with a credit card. In case of fraud (e.g. hacked payment provider), recovering from ACH fraud is much harder than recovering from a credit card fraud. While you will likely get your money back at the end, it is also likely that you will spend many months talking to your bank (not to mention returned checks or other payments in the meantime).<p>Overall, I strongly recommend to NEVER pay via ACH from an account that is used for other purposes. Personally I have a special account at my bank just for rare ACH payments I need to make. I can transfer money instantly from my primary account when I need to make a payment. And of course this special account has all the overdraft protections, etc. disabled.