## TL;DR
Fix this in bank account change agent by acting on the exact problem first: treat the callback verification as its own saved step, record the change request and the callback number taken from a source already on file before any call is made, complete and log the callback outcome separately, and only then submit the bank change with that logged outcome attached so a timeout never leaves the change half submitted. Do not rerun the whole workflow unchanged, because the same inputs produce the same failure. Prove the fix on one vendor first, then rerun the full scope and reconcile the results.

```text
agent failed to process vendor bank account change request with callback verification error failure timeout
```

## Use this when
- The operation in bank account change agent fails with this exact problem: agent failed to process vendor bank account change request with callback verification.
- The same failure repeats on retry with unchanged inputs.
- A vendor onboarding, payment setup, screening or vendor record step is blocked until this is resolved.

## Not for this skill when
- The notice is a platform outage from the vendor of the tool. Resolve that first, then return here if this problem remains.
- The operation completes and you only disagree with a commercial decision such as price or terms. That is a negotiation, not this failure.

## Steps
1. Reproduce the failure on one named vendor in bank account change agent and record the full problem text plus the vendor, supplier record or onboarding case involved. Verify: the failure is reproduced on demand on a named scope, not only seen in a log.
2. Apply the specific fix for this problem: treat the callback verification as its own saved step, record the change request and the callback number taken from a source already on file before any call is made, complete and log the callback outcome separately, and only then submit the bank change with that logged outcome attached so a timeout never leaves the change half submitted. Verify: the single failing vendor now behaves as the fix predicts, or the corrected value is visible on the record.
3. Check neighbouring vendors, supplier records or onboarding cases that share the same automation, template or sync, because this class of failure rarely affects only one vendor. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Rerun the original operation in bank account change agent on the previously failing scope, watching for the same problem rather than assuming success from a quiet log. Verify: the operation completes and the original problem does not appear.
5. Compare the result against the source of truth, the vendor master record, the signed tax form or the compliance document, so a silent partial success is caught. Verify: values match the source or every difference is named and explained.
6. Record the fix, the triggering input and the verification result on the vendor record so the next occurrence is recognised immediately. Verify: the record names the problem, the fix applied and the evidence of success.

## Variant phrasings

### agent failed to process vendor bank account change request with callback verification
The verbatim form searchers paste from the console, report or run log. Treat it identically: same fix, same single vendor proof, then the full rerun.

### How to fix - agent failed to process vendor bank account change request with callback verification error failure timeout
The how to phrasing for the same failure in bank account change agent. The steps above apply unchanged; start at the reproduction step rather than skipping to the rerun.

### bank account change agent troubleshooting for this failure
The symptom first phrasing used when the console hides the full problem. Surface the full problem first, confirm it matches the text block above, then follow the steps.

## Why it happens
The callback depends on reaching a known vendor contact in real time, and an agent that bundles the call, the wait and the submission into one run times out and cannot prove whether verification happened.

## Edge cases
- The vendor was merged, renamed or given new banking details after the failing run started. Refresh the vendor state and reapply the fix against the current values, not the values from the failed run.
- The single vendor proof passes but the full rerun still fails on other vendors. Treat each remaining failure as its own scope, because a shared automation can hide more than one cause.
- The source systems disagree on the correct value. The vendor master record governs identity and payment details, the signed tax document governs classification and withholding, and the compliance screening governs approval status; record which source won and why.

Compatibility: bank account change agent at current versions, plus the procurement, ERP or screening platform the query names; no extra tooling beyond access to the source records needed to verify results.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_AYLRXqgdnILZiTq6cKoy0Q