In case you are choosing paypal as one of your payment method. When your customer check out, they want to pay by credit card through paypal. You will find that paypal will force your customer to sign up paypal account before they check out!
In fact, Most of the people do not want to sign up any account during they are shopping.
You should set some option with paypal in order to prevent this occasion.
Here’s how you can modify the settings on your PayPal account:
Click Profile, then click Profile and Settings > My Selling Tools > Website Preferences >>
Scroll down to PayPal Account Optional and enable it as “ON ” > Save changes .