WP SmartPay Pro lets you add a surcharge to any payment form — either a flat fee or a percentage of the subtotal. This is useful for covering processing fees, adding a convenience charge, or including a platform fee on top of the base price.

Where to Configure It

  1. Open the form: SmartPay → Forms → Edit.
  2. In the right sidebar, expand the Pricing panel.
  3. Locate the Additional Charges section (Pro).
  4. Toggle Enable Additional Charge to on.

Charge Type

  • Flat Fee — A fixed amount added to every payment, regardless of the subtotal. For example, a $2.00 handling fee.
  • Percentage — A percentage of the payment amount. For example, 3% to pass on credit card processing fees.

How It Appears at Checkout

When an additional charge is configured, the checkout form shows an itemised breakdown before the pay button:

  • Subtotal (the base form amount)
  • Additional charge label + amount
  • Total

This transparency helps customers understand what they are paying before clicking the pay button.

Impact on Invoices

If the Pro invoice feature is enabled, the additional charge appears as a separate line item on the auto-generated invoice. This keeps the invoice accurate for accounting purposes.

Common Use Cases

  • Passing on card fees — Add a 2.9% + $0.30 surcharge to recover credit card processing costs.
  • Platform fee — If you are collecting money on behalf of a third party and retaining a percentage.
  • Convenience fee — A flat fee for accepting online versus cash/cheque payments.
Note: Some regions have regulations on passing credit card surcharges to customers. Check your local laws before enabling a processing fee surcharge.