Downgrading from 'Super'/'Fast' Fibre to standard Fibre

iniltous

As a Now customer you don’t have a BTw number so you have to use the address option rather than phone number , but the post you replied to,  does say to use phone  or the address.
TBH , as you haven’t provided any real data , apart from saying you get 38Mb from a 40Mb service , it’s not possible to predict if you will get better speed from the higher profile , but if your line is only capable of 38 Mb then the higher profile won’t change that , if your line is being limited to 38 not because of the distance to the cabinet but because you are on a 40Mb profile and with ‘overheads’ reducing observable speed to 38Mb , your  line may be hitting the 40Mb barrier of that profile, then you may get faster speeds on the higher profile, as it is without router statistics or the BTw prediction, it’s impossible to know ..38Mb is a tricky speed as it is so close to the 40Mb  limit of the lower profile, the speed shown on a speed tester is always lower than the headline speed because of the way Ethernet and speed testers work