Yes, if the website or the vendor accepts PayPal. You can log-in to your account. You can pick to use your balance through your account. If they do not accept PayPal, I believe you won't be able to use your balance.
You can use funds in your paypal balance 'as long as' they are in the correct currency and not pending.
BUT for some transactions ie digital / virtual or higher risk AND at 'some point' anyway Paypal will ask you to add a card to act as a back up funding source and to verify your Paypal account.
Advice is voluntary. Kudos / Solution appreciated.
the most famous website that will let you use your balance is Ebay.
What you need to remember is, you need to see the "Login to Paypal" which sometimes appears where you put your CC information. Look for the login button.
