Corporate cards (Amex Corporate, Visa Business, Mastercard Corporate), purchasing cards (P-Cards), and virtual AP cards (Coupa, Bill.com, Tipalti issuer cards) carry materially higher interchange than consumer credit cards. Without Level 2/3 enhanced data — invoice number, PO, tax amount, line items — every B2B card transaction downgrades to the most expensive non-qualified bucket, costing 30–80 basis points more than necessary.
The fee shows up two ways. On flat-rate processors (Stripe, Square, PayPal) it's invisible because every card pays the same flat rate — you absorb the loss silently. On interchange-plus, you'll see the high downgrade interchange itemized; passing Level 2/3 data automatically requalifies the transaction at the lower commercial-card rate. Most B2B operators leave 50+ basis points on the table by not enabling Level 2/3.