Available until midnight tonight. (30/06/2020)
"Online only", so you can't use this if ordering over the phone.
Notable since not restricted to new customers this time.
Edit: Now locked down to New Customers only! :(
Due to misuse we've had to lock it down to our standard rules. You cannot use the promo code if you have a current service, or have disconnected in the last 6 months. If you are a new customer you're all gravy baby.