If you've referred a friend, the referral credit will be added to your Bulb account once their switch to Bulb is complete. This normally takes 21 days.
If you're switching to Bulb after being referred by a friend, you'll get the credit when your switch is complete.
You can check on the status of the referral in your Bulb account.
Top up (or prepay) meters
If you're switching to Bulb with a top up meter (also called a prepay meter), your credit will be sent through Transferwise after your first electricity top up. They'll email you to ask for your bank details 1 or 2 days after your top up. It can take 1 to 3 working days for your credit to arrive in your account after TransferWise sends it.