We have a Zen Fibre Office package, which we've had for over a year and is now out of its contact period. Because our bandwidth usage for the last 3 months has been way below its limit of 400GB, we thought it would be good to regrade down to the next package, Fibre Pro, to save about £20/mth with VAT.
To my surprise I was told while we can downgrade, it would trigger a new 12 month contact, thus should we want to regrade back up again, we'd have to pay out the remainder of that contact.
The excuse for this is that the next package down has a lower minimum download speed.
Never heard of such issues with an ISP before who are usually happy for you to be paying for the next package up in the future.
Just a warning to anyone out there who are thinking of joining or regrading.