To make an Instant Bank Transfer you must have an up-to-date credit or debit card registered to your PayPal account, as well as your bank account. This will be used as a back-up funding source in case the bank transfer fails.
You can add a credit or debit card by selecting the ‘Profile’ link at the top of your Account Overview page and clicking the ‘Credit Cards’ link under ‘Financial Information’.
PayPal has changed the layout, slightly, since that help page was produced. The route for adding a credit/debit card is now: My Account > Profile > My Money.
