No, you don’t need to have a PayPal account to pay an invoice on a website that accepts PayPal. Most websites offer an option to pay via PayPal as a guest, which allows you to use a credit card or debit card without creating a PayPal account. When you select PayPal as your payment method, you should see an option to "Pay with Debit or Credit Card" or "Pay as a Guest," where you can enter your payment details directly.