If a Referred Friend subsequently cancels...

The Welcome Pack’s Terms and Conditions include this one : -

16.2.4. Cancellation: If the sign up to Bulb by the Referred Friend is subsequently
cancelled, this will result in the cancellation of the Referrer’s Reward and the
Referred Friend’s Reward.

For how long is this relevant ? As Bulb do not charge exit fees, is there a minimum amount of time that a referred friend must stay with Bulb before switching ?

As soon as the switch is fully complete they can leave and you will still get to keep the referral money, it’s only if they cancel(or the move gets declined by the current provider) within the initial 21 days switching period

Ah, that makes sense ! Thanks.

Hey both, @Reg , @tom6685 is correct here. Once the switch has gone through, the referral credit is added onto your account usually within 3 days.