How long does it take for a referral to appear on my account in the switching section

It should appear a day or two after the switch date of the person you referred (which is normally 21 days after the start the signup process).

Just to add to what mowcius said, if you’re just talking about the person’s name appearing in your ‘currently switching’ section, then this should happen on the day they sign up using your link and you should receive a confirmation email as the referrer. The actual £50 credits should be added to both accounts automatically on the switch date and again as the referrer you should receive email confirmation of that too.