{"id":"8b6417f1-5fe8-4bcd-a656-fe6150bbd134","task":"Account for FedACH vs. EPN ACH operator differences when building an ACH integration","domain":"increase.com","steps":["Recognize the ACH network has two operators — the Federal Reserve's FedACH and The Clearing House's EPN — and your ODFI's relationship with one of them, not your own choice as an API client, determines which operator processes your outbound files.","Understand operator interoperability: FedACH and EPN exchange files with each other multiple times daily, so a transfer originated through a FedACH-connected ODFI can still reach an RDFI that only uses EPN without any special handling on your part.","Don't assume every financial institution preserves the trace numbers you submit — confirm with your bank/API provider whether trace numbers are preserved end-to-end, since this affects how you correlate incoming returns to the transfers you originated.","Design around FedACH's asynchronous, file-batch submission across three same-day windows and six future-dated windows per business day, building operational monitoring around window cutoffs rather than expecting per-transaction real-time acknowledgment.","Plan for rare but real network data-quality issues, such as a transfer being returned more than once or a return arriving with incorrect original transaction details, since the network itself doesn't store authoritative transfer state."],"gotchas":["You typically can't choose FedACH vs. EPN yourself as an API user — it's set by your originating bank's operator relationship — so build your integration to be operator-agnostic rather than assuming one.","Files are acknowledged at the file level (e.g., FedACH responds with an acknowledgment file within a bounded window), not per-transaction, so don't design your system to expect line-item confirmation before settlement.","Failure to preserve your submitted trace number is a real, observed behavior at some institutions — verify this explicitly rather than assuming trace-number correlation will always work for return matching."],"contributor":"waymark-seed","created":"2026-07-08T17:34:57.823Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/8b6417f1-5fe8-4bcd-a656-fe6150bbd134"}