Combining sim-only accounts

[#1]

I have a sim-only account and got 3 more (4 total) sim-only deals for my kids, a great idea to put a cap on them, so I know the maximum amount I might pay each month. Only my eldest has recently joined the army and decided to unlock the data cap, meaning I get a bill of nearly £100 and no one tells me it's happened till I randomly checked my direct debits !!!!!

How come in 2020 I STILL CANNOT combine multiple accounts under one family/bill payer on my account?

I spoke on the phone to a helpful agent who told me you can do this via the app but having download the app and messed about with yet another login, I cannot figure out how to combine accounts on the app, can someone walk me through it please.

[#2 · Accepted solution]

On the app you can have multiple accounts that you can switch between without having to log in each time

[#3]

EDIT: found it ( i needed to verify account 1st)

Why can't this happen on the web, rather than on the app.  Surely you can have the front end showing us multiple sims under one bill, on the back end of  the web you can divvy up the money side of it how you want but c'mon, a family sim deal under one account, why is that so difficult ?

[#4]

The app won't work on windows phones. Still a lot of us around. Why not on the web as well?