Why adding wallet credits doesn't work for a finalized invoice that failed payment

Once an invoice is finalized, wallet credits can't be applied to it retroactively, even if the wallet is topped up afterward. Retrying payment on a finalized invoice goes directly to the configured payment provider using the amount calculated at finalization; Lago doesn't re-evaluate the wallet balance.

How it works

Wallet credits are applied during finalization, before payment is attempted. After finalization, the invoice amount is fixed, and any subsequent payment retries use that fixed amount.

How to resolve it

Void the failed invoice. Voiding automatically returns any wallet credits already applied to that invoice to the customer's wallet, no need to manually top it up first. Then regenerate the invoice using the Regenerate option in the UI (available on voided invoices, not currently accessible via the REST API). Lago applies the available wallet credits during the new invoice's finalization, reducing or eliminating the amount sent to the payment provider.

This article reflects guidance drawn from customer case resolutions. It is not officially supported documentation and may not apply to all situations.