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When testing your application, you will want to test both successful and failed scenarios. By default, invoices and transactions in the Mercoa test environment will be successful, but you can use certain values to trigger errors.

## ACH Payments

By setting the `noteToSelf` (the description field) field to specific values, you can trigger the following events:

For all of these test values, the `deductionDate` will be ignored and the invoice will be processed as soon as it is scheduled.

| Value                          | Description                                                                                                                                             | Outcome                                                                                                                      |
| ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------- |
| `MERCOA-ERROR-R01`             | `Insufficient funds: The account has insufficient funds to complete the transaction`                                                                    | Invoice will be marked as FAILED, associated transaction will be marked as FAILED, source bank account will be frozen        |
| `MERCOA-ERROR-R02-SOURCE`      | `Account closed: Previously active account has been closed by customer, or RDFI`                                                                        | Invoice will be marked as FAILED, associated transaction will be marked as FAILED, source bank account will be frozen        |
| `MERCOA-ERROR-R02-DESTINATION` | `Account closed: Previously active account has been closed by customer, or RDFI`                                                                        | Invoice will be marked as FAILED, associated transaction will be marked as REVERSED, destination bank account will be frozen |
| `MERCOA-ERROR-R03`             | `No account located: Account number structure is valid and passes editing process, but does not correspond to an individual, or is not an open account` | Invoice will be marked as FAILED, associated transaction will be marked as REVERSED, destination bank account will be frozen |
| `MERCOA-ERROR-R04`             | `Invalid account number: Account number structure not valid. Entry may fail check digit validation, or may contain an incorrect number of digits.`      | Invoice will be marked as FAILED, associated transaction will be marked as REVERSED, destination bank account will be frozen |
| `MERCOA-ERROR-R29`             | `Originator unauthorized: The RDFI has been notified by corporate receiver that debit entry of originator is not authorized`                            | Invoice will be marked as FAILED, associated transaction will be marked as FAILED, source bank account will be frozen        |
| `MERCOA-SUCCESS-INSTANT`       | `Instantly marked as paid`                                                                                                                              | Invoice will be marked as PENDING and then immediately marked as PAID, associated transaction will be marked as COMPLETED    |