ACH vs wire for large B2B payments — which is safer?

Starting to get enterprise clients paying $20-50K invoices. They're asking for ACH or wire instead of credit card (makes sense, 3% fee would be brutal). Which is safer from my perspective as the vendor?

Wire transfers are essentially irrevocable once sent. ACH can technically be reversed within 2 business days (or longer for fraud claims). For large amounts where you trust the client, either works. For new relationships, wire is safer.

we do both. wire for first payment from new clients, ACH for ongoing if they're established. wire fees are $25-45 which is nothing on a $30K invoice

IMPORTANT: wire fraud is real. always verify wire instructions by phone using a number you already have (not one from the email). scammers intercept emails and change bank details. I've seen companies lose six figures this way

@FraudRisk yes, this happened to us as the payer. Our email was compromised, fraudster sent fake invoice with their bank details to our client. Client wired $45K to the wrong account. Took 6 months and lawyers to sort out who was liable. verify verify verify

Scary stories. How do you guys handle sharing bank details securely? Just send routing/account in a PDF invoice?

I put bank details on invoices but also include a note: "Please verify wire details by calling [phone] before sending large amounts." Some clients also use bill.com or similar platforms which handle the verification automatically.