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

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.

Context from the original thread: 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.

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