I seriously think BT have got this wrong and it needs fixing.
BT plc t/a Openreach provide GEA links (basically what most ISPs use to provide FTTC) on a 12 month minimum term.
Firstly, this is a problem anyway - most other services whether broadband or phone line - do not have a minimum term. This may have made more sense in the start and when there was an engineer visit and modem supplier, but really starts to make no sense for wires only FTTC, and now that FTTC is the norm. So ideally BT need to drop the minimum term. However, for now we have it.
When migration of FTTC services came in there was a problem - BT would charge the old ISP for the end of the term whilst charging the new ISP for the same period of time and holding the new ISP to a new 12 month term. What was even worse is that this was done by BT plc t/a BT Wholesale. Their excuse was that BT plc t/a Openreach had this 12 month term. However a migrate from one BTW customer to another BTW customer did not involve BT plc t/a BT Wholesale restarting the term with BT plc t/a Openreach - they literally were charging two ISPs for the same service for the same time!
The eventual fix was to make a migrate not have a min term for the new ISP but the old ISP pays to end of term. It addresses one issue, but has some serious problems.
The issue here is that when two parties agree a contract and dictate something like a minimum term, it make sense for the party that breaks that term and ceases before the end of the minimum term to compensate the other party.
So, if an ISP buys a service with a 12 month term and ceases after 6 months, it makes sense to pay the supplier / carrier something, perhaps even the whole of the remaining 6 months of service.
But what if the supplier (carrier) breaks the term - and ceases the service within the 12 months. Then surely the supplier needs to compensate the ISP for that breach, at the very least not expecting the ISP to pay to term for a service that is not being provided.
Sadly BT plc t/a BT Wholesale do not agree - they think that even when they break the 12 month minimum term the ISP has to pay them for the remainder of the term!
Now, this only really happens if the service is transferred to a new ISP. But even so, it is the carrier breaking the term with the ISP and not the other way around.
Now, if BT plc t/a Openreach insist on a 12 month term, what would make sense in the case of a transfer is for the new customer to be starting a new 12 month term, and the old customer to be let off. That would mean that the carrier would not have to pay BT plc t/a Openreach when it is BT plc t/a Openreach that breaks the term, and similarly BT plc t/a BT Wholesale would not have to charge the ISP for the rest of the term when it is BT plc t/a BT Wholesale that broke the term, and ultimately the ISP would not need to charge their customer an early termination fee.
Even better would be for a migrate to carry over the remaining term and not restart the 12 months. This would ensure BT plc t/a Openreach always got 12 months rent for a VDSL port that they have installed, which is what they want.
But ultimately the best would be for BT plc t/a Openreach to just drop the minimum term on the wires only FTTC installs and then it would avoid a lot of unfair contract terms and arguments.
P.S. One carrier is being very very special, suggesting early termination means not only paying to term but also paying an extra early termination fee. That is crazy - why would you cease the service early rather than just leave it in place to end of term in that case.