I had to keep two phones for this purpose[0] and pay two cellphone bills, one in the USA and one in the UK. It helped when traveling in Europe though because then you are only paying UK data rates, not USA-on-vacation rates.
It is still an insane situation, though.
[0] LloydsTSB had the same restriction on app store
You can purchase data-only sims that last a couple of years in the UK with generous monthly data allowances for a one time upfront fee. May save you overpaying for two separate bills.
It is still an insane situation, though.
[0] LloydsTSB had the same restriction on app store