That’s exactly how many back end payment processors work in Canada. Banks would even rather pay a third party to handle things like (what we have called) Interac email money transfers than do the work in house as it saves on large amounts of overhead, administrative and insurance costs.

You’ve got a good niche and I have to admit I’m envious of the position you’re in—that level of autonomy seems rare.

It’s also a stupidly great idea for non-technical trade and craft shows. No infra or complex setup needed. Smart. Well done.