Understanding the “INVALID USAGE A73 57” Error 💳
When attempting to process a credit card transaction, you may encounter the error message:
INVALID USAGE A73 57
This message indicates an issue with how the merchant account is configured at the processor level — specifically related to Hold Capture settings.
⚙️ What This Error Means
The INVALID USAGE A73 57 error occurs when your merchant account is not configured for Hold Capture.
NX uses a Pre-Authorization and Capture model when processing credit card transactions.
In this workflow:
- A Pre-Authorization (PreAuth) is first created when the card is run.
- Later, during batch settlement, NX sends a Capture request to finalize the transaction and transfer funds.
If the merchant account is not properly configured to allow this Hold Capture process, TSYS returns the INVALID USAGE A73 57 error.
🧩 Common Cause
This issue is most commonly seen when the Capture Delay Flag in TSYS Express is not set correctly.
- Incorrect setting: The Capture Delay Flag is not defined or is set to an incompatible value.
- Correct setting: The Capture Delay Flag should be set to “H” (Hold Capture).
When set to Hold Capture, the processor expects NX to perform both parts of the transaction (PreAuth and Capture), which matches the NX workflow.
🧰 How to Resolve
You will need to contact your payment processor (the merchant services provider that manages your TSYS Express account) and request the following:
“Please set the Capture Delay Flag to ‘H’ for Hold Capture in TSYS Express.”
Once your processor updates the setting, the error will no longer occur when running credit card transactions.
🧭 Additional Notes
- This configuration must be corrected by your processor — it cannot be changed in NX or by Datacap.
- After the change, most processors do not require a restart or reconfiguration on the NX device.
- If the issue persists after the processor update, try performing the following:
- Restart NX POS on all terminals.
- Run a test transaction to confirm successful approval.
- Check your logs in the NX Portal for confirmation that PreAuth and Capture are processing normally.
💡 Related Terms
| Term | Definition |
|---|---|
| PreAuth (Pre-Authorization) | A temporary hold on the customer’s funds to verify card validity and availability. |
| Capture | The process of finalizing a pre-authorized transaction, submitting it to the processor for settlement. |
| Hold Capture Mode | A merchant account setting that allows transactions to be authorized and later captured. |
| Batch Settlement | The daily process where approved transactions are finalized and funds are transferred. |
✅ Summary
If you encounter INVALID USAGE A73 57 when running a credit card, it means your merchant account is not configured for Hold Capture.
Solution:
Contact your processor and have them set the Capture Delay Flag to “H” (Hold Capture) in TSYS Express.
Once this is corrected, NX will be able to process credit card transactions normally.