WHMCS crypto payment integration checklist

This is an integration checklist for WHMCS billing flows that need crypto checkout, webhook-backed payment updates, support-visible invoice references, and finance reconciliation.

Implementation flow

  1. Create or load the WHMCS invoice and keep its ID as order_id.
  2. Create a SwapSS Pay invoice from your server. See invoices.
  3. Redirect the payer to the returned payment_url.
  4. Verify webhook signatures before marking a WHMCS invoice paid. See webhooks.
  5. Reload invoice state and use payment statuses before provisioning service.
  6. Store invoice, webhook, status, and ledger evidence for reconciliation.

WHMCS invoice mapping

WHMCS valueSwapSS Pay valuePurpose
Invoice IDorder_idConnects billing, support, and finance records.
Gateway redirectpayment_urlSends the payer to the hosted crypto checkout.
Transaction noteInvoice public IDGives support a stable reference.
Service provisioningInvoice statusPrevents activation before the payment is safe.

Provisioning guard

Do not activate hosting, licenses, or subscriptions from a raw redirect alone. Verify the webhook, reload the invoice status, and provision only when the status page classifies the payment as safe for delivery.

Related docs: quickstart, webhook verification, statuses, and reconciliation.