Although iOS tries to turn phone numbers in many apps into clickable links, this doesn’t work everywhere, and can be especially troublesome for “vanity” phone numbers such as 1-800-MY-APPLE. In these cases, however, you can take advantage of a hidden feature in iOS and simply paste your number right into the Phone app from the iOS clipboard.
Simply copy the number to the clipboard as you normally would, and then open the Phone app to the “Keypad” section and tap and hold on the blue phone number display section above the keypad and the standard “Paste” option should appear. As an added bonus, when pasting in a vanity phone number, it will be converted to its numeric form with the original alphanumeric version displayed in a smaller font below. Note that this also works in the other direction—a phone number already displayed in the Phone app can be copied TO the clipboard using the same standard tap-and-hold gesture.