Can an international ACH payment require wiring?

reapnleap

Hi,
I asked my bank (credit union in the US) if they charged any fees if I receive an ACH payment from a business client in Canada. My bank said the technically ACH is free, but that it depended on how Wave or Plaid handled international transactions. If it's wired, then my bank charges a fee.

I can't find any information on how wave or Plaid technically handle international ACH transactions. What would determine if the typical ACH approach won't work and they have to use wiring?

I'm just trying to find out if invoicing via wave and asking for ACH payment would be a viable option (without hefty fees). I know wave charges 1% for ACH payment. I'm trying to figure out what might technically make ACH payment not feasible between my client in Canada and my US bank. It's a small bank. They aren't even searchable via Plaid.

Thank you!
reapnleap