I've just re-contracted my broadband with BT (yes, yes I know they're not the cheapest, but I'm quite restricted to who I can use where I live and I'm happy with their service) and noted this in their contract terms:
As of 13 December 2019, we own all BT Broadband Hubs (Hub 4, Smart Hub, Ultrafast Smart Hub and Smart Hub 2) and TV Boxes (Z4, G4 and G5) sent out to customers. Not applicable for Hubs and Wi-Fi Discs purchased outright.
- When you replace hubs or boxes, or leave BT, please return those items to us. If the kit is not returned, you may be liable for a charge. Details of charging can be found on the Tariff Guide.
- You have a total of 60 days to return your items and which includes the time taken for us to send out a jiffy bag.
- If you prefer, you may also drop your items off in an EE store (see BT.com/returns for more details). They tried to encourage me to take a SmartHub for £0.00 and probably hoped I wouldn't notice the £9.99 activation/postage fee being added to the bottom line, but I didn't fall for that one. The box I had to tick to turn it down said something like 'Please be aware that most non BT routers do not work on our broadband service'
I'm glad they're now treating these as loan items, as hopefully far less of them will end up in landfill. I expect a lot less will end up on eBay too.
I still have a SmartHub in a cupboard, and I think a Hub 5 too, so if I have issues I can plug one into the line to stop them moaning about unsupported equipment.