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.

WP SmartPay form editor Pricing panel showing Additional Charges toggle, charge type selector, and amount field
The Additional Charges section inside the form editor Pricing panel — toggle it on to reveal charge type and amount.

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.