Why is a surcharge added for PayPal payments?

A 2.5% surcharge will be added to orders made outside of the United Kingdom using PayPal as the payment option.

PayPal imposes several mandatory charges related to national borders and currency conversions, which result in higher fees for us compared to other payment methods. These fees are about three times higher overall. We still offer PayPal for customers who prefer it but we need to pass on some of these costs.