ACH monitoring
ACH and Nacha monitoring with BankBridge
How ChargeWarden reads BankBridge ACH entries and returns, calculates rolling 60-day return rates against the Nacha levels, records WEB debit account validation and builds a monthly evidence report.
Last updated by the PluginLoom team
When BankBridge takes bank payments through Plaid Transfer, ChargeWarden keeps a ledger of every ACH entry, its return code and how the account was validated. ChargeWarden > ACH monitoring shows return rates, validation coverage and the monthly report.
This module supports your own risk-based fraud monitoring process. It is not a certification and does not show that you comply with the Nacha Operating Rules. Your bank calculates official figures from every entry you originate through it.
Which Nacha rules does it relate to?#
| Rule | Date | What it asks |
|---|---|---|
| WEB debit account validation (opens in a new tab) | In force since 19 March 2021 | The fraud detection system for online consumer debits must "at a minimum, validate the account to be debited", on the first use of an account number and when it changes |
| Fraud monitoring, Phase 1 (opens in a new tab) | 20 March 2026 | All ODFIs, and non-consumer Originators, Third-Party Service Providers and Third-Party Senders with annual ACH origination volume of 6 million or more in 2023 |
| Fraud monitoring, Phase 2 (opens in a new tab) | 19 June 2026 (in practice Monday 22 June 2026, as 19 June was a federal holiday) | All other non-consumer Originators, Third-Party Service Providers and Third-Party Senders, and all remaining RDFIs |
| Return rate levels (opens in a new tab) | Unauthorized level 0.5% since 18 September 2015 | Unauthorized 0.5%, administrative 3.0%, overall 15.0% |
The fraud monitoring rules ask covered parties to "establish and implement risk-based processes and procedures ... reasonably intended to identify Entries that are suspected of being unauthorized or authorized under False Pretenses", and to review them at least once a year. Nacha says monitoring before processing is not required. All dates and quotes were checked at nacha.org on 24 October 2026.
How are return rates calculated?#
| Family | Return codes | Nacha level |
|---|---|---|
| Unauthorized | R05, R07, R10, R11, R29, R51 | 0.5% |
| Administrative | R02, R03, R04 | 3.0% |
| Overall | Every return code | 15.0% |
Each rate is the number of debit entries returned in the last 60 days divided by the number of debit entries originated in the same 60 days. This is one of the two methods in Nacha's calculation guides (unauthorized (opens in a new tab), administrative and overall (opens in a new tab)). Credits (payouts) are not counted. Nacha notes that the administrative and overall levels start an inquiry; they are not automatic rule violations.
When will I get an alert?#
Once a day ChargeWarden compares each rate with its level. You get one email when a rate first reaches the watch fraction (default 0.5, so 0.25% for unauthorized) and again at the warning fraction (default 0.8). Both are in Settings > ACH monitoring.
How is account validation recorded?#
When BankBridge creates a debit, ChargeWarden saves a snapshot of how the account was connected, on BankBridge's own transfer record (through the bankbridge_transfer_record_meta filter) and in its ledger:
| Method recorded | Meaning |
|---|---|
| Plaid Auth: shopper logged in to their bank | Instant account connection through Plaid Link |
| Plaid Auth: automated micro-deposit verified | Plaid's automated micro-deposits confirmed |
| Plaid Auth: same-day micro-deposit verified by the shopper | The shopper confirmed the micro-deposit amounts |
| Plaid database check passed | Plaid's database match |
| Validation pending or failed | Micro-deposits not yet confirmed, or failed |
| Not recorded | The entry was made before ChargeWarden was installed and the account no longer exists |
The ledger also marks the first use of each account (by a keyed hash of Plaid's account ID; account and routing numbers are never stored). The ACH screen and the report list first-use WEB debits without a recorded validation so you can follow up.
Run wp chargewarden nacha sync, or Read all entries from BankBridge again on the ACH screen, to backfill entries made before ChargeWarden was installed.
What is in the monthly report?#
Download PDF report and Download CSV on the ACH screen, or wp chargewarden nacha report --month=2026-09 --format=pdf --output=report.pdf:
- The statement that the report supports your own process and is not a certification.
- Return rates over the 60 days ending on the last day of the month, with status.
- Volume by debit or credit and SEC code.
- Returns received in the month by code.
- WEB debit account validation, by method, with any first-use debits lacking a record.
- The checkout fraud controls in place and the month's activity.
- A space to record who reviewed the report and what changed.
Fill in your company name, bank, process owner and the date of your last annual review in Settings > ACH monitoring so they appear on the report.
What can it not see?#
- Entries originated by another processor. BankBridge's processor-token mode (Stripe, Dwolla and others) has the processor send the debit, so its returns are in the processor's dashboard, not in BankBridge.
- Entries you originate outside this website.
- Whether your bank counts the same 60 days. Ask your bank which method it uses.
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