Obtain the clearing data files from your processor or acquirer; these are typically fixed-width or CSV files in a processor-specific format derived from Visa BASE II, Mastercard IPM, or equivalent network clearing formats
Parse each transaction record to extract the interchange rate qualifier (IRQ) or interchange program identifier (IPI), the gross transaction amount, the interchange amount, and the assessment fees (scheme fees, network access fees) separately
Group parsed records by interchange category (e.g., Visa Retail, Visa Business, Mastercard Consumer Credit) and sum gross amounts and interchange charges per category; compare totals against the interchange fee schedule published by the network
Identify downgraded transactions by finding records where the IRQ indicates a base category (EIRF, Standard) rather than the expected qualified category; quantify the interchange premium paid on downgrades
Reconcile the per-transaction interchange sum to the processor's monthly interchange invoice line items; differences indicate either a processing fee markup, a posting-period mismatch, or a reconciliation file that covers a different date range than the invoice
Known gotchas
Interchange rates are updated by Visa and Mastercard twice yearly (typically April and October); reconciliation logic using hardcoded rate tables will drift — fetch current rates from your processor's rate API or published schedule
Assessment fees (Visa Acquirer Processing Fee, Mastercard Cross-Border Assessment, etc.) are billed separately from interchange and appear as distinct line items; summing only interchange without assessments will undercount total card network costs
Some processors net interchange into the discount rate rather than passing it through separately; in a bundled pricing model, the clearing file interchange values reflect network actuals but the processor invoice shows only the bundled rate — the two should not be directly compared
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp