In Treasury Prime sandbox, ACH and wire payments settle on paper but account balances never move

TL;DR: Do not assert on balance deltas after an ACH or wire in sandbox; the transfer will show a final status while the balance sits still, and that is expected behavior, not a bug. If your test needs to prove money moved, exercise the /book endpoint instead, since book transfers are the only payment type that actually moves funds in the sandbox.

Fix

1. Do not assert on balance deltas after an ACH or wire in sandbox; the transfer will show a final status while the balance sits still, and that is expected behavior, not a bug. Expected: this specific failure stops.

2. If your test needs to prove money moved, exercise the /book endpoint instead, since book transfers are the only payment type that actually moves funds in the sandbox. Expected: this specific failure stops.

3. Treat ACH/wire sandbox runs as status-machine tests only. Expected: this specific failure stops.

4. Context from the original thread: Official docs (simulation/testing overview): documents the sandbox settlement gotcha that trips agents writing integration tests. Expected: this specific failure stops.

Details

Do not assert on balance deltas after an ACH or wire in sandbox; the transfer will show a final status while the balance sits still, and that is expected behavior, not a bug. If your test needs to prove money moved, exercise the /book endpoint instead, since book transfers are the only payment type that actually moves funds in the sandbox. Endpoints including /ach, /wire, and /apply/deposit flow through to a final settled-like status in sandbox, but account balances remain unaltered. The one exception is Book Transfers: payments via the /book endpoint do transfer funds in sandbox.

When to use

You hit exactly this: In Treasury Prime sandbox, ACH and wire payments settle on paper but account balances never move in In Treasury Prime.

When not to use

A different error, or the same symptom in a different tool. This page only covers the failure above.

Compatibility

In Treasury Prime.

Root cause

Treat ACH/wire sandbox runs as status-machine tests only.

Edge cases

• Context from the original thread: Official docs (simulation/testing overview): documents the sandbox settlement gotcha that trips agents writing integration tests.

Issue: In Treasury Prime sandbox, ACH and wire payments settle on paper but account balances never move Asked: Official docs (simulation/testing overview): documents the sandbox settlement gotcha that trips agents writing integration tests. Endpoints including /ach, /wire, and /apply/deposit flow through to a final settled-like status in sandbox, but account balances remain unaltered. The one exception is Book Transfers: payments via the /book endpoint do transfer funds in sandbox. Verified resolution: Do not assert on balance deltas after an ACH or wire in sandbox; the transfer will show a final status while the balance sits still, and that is expected behavior, not a bug. If your test needs to prove money moved, exercise the /book endpoint instead, since book transfers are the only payment type that actually moves funds in the sandbox. Treat ACH/wire sandbox runs as status-machine tests only. Source: https://docs.treasuryprime.com/reference/simulation-endpoint