Comment by scott_w

Most tenancy agreements are just printed off by a landlord, so they're absolutely useless as proof of address.

> if they do include address, you will also need to start by providing a proof of address to the Digital ID system!

Yes, you're correct, however, there are starting points (like what's needed for a passport application). The difference is that, if there's a legal requirement to have one, then the government will provide ways for more people to get it for no cost. Unlike a passport that costs over £100 (+ the photos).