Can I use Billforward for one-time transactions?

Yes, you can.

Billforward supports one-off bills and invoices and also allows you to manually add one-off line items to recurring subscriptions.

Manual invoice

To create a manual invoice, open the account and click the Actions button in the top right. Select Add Invoice.

actions, add invoice
Custom charge on existing subscription

To add a custom charge, open the subscription and click Actions > Add Custom Charge. The charge will be collected next time an invoice is issued for that subscription.

actions, add custom charge
One-time payments in Flexcheck

The process for taking one-time payments with Flexcheck is a bit different — please follow the instructions in this article.