You can pass on the surcharge, but it’s against some countries’ laws to impose an additional surcharge. We recommend that you check the terms on Paypal or Stripe to verify their terms around surcharges.
Studio Ninja doesn’t have the ability for photographers to pass on the surcharge automatically.
If you know your client is definitely paying by credit card (or if that’s the only option you give), and wish to pass on the surcharge, we suggest having a line item on the invoice called Administration fees or Handling fees.
You can permanently setup an Administration fee in your Settings > Products / Packages page for quicker invoicing.
Alternatively, you can factor credit card surcharges into your costs of business.