I would really rather not carry two phones around

Are there any handsets that take two SIM cards?

Plenty of Android ones. Some have a passive setup where you need to reboot the phone or manually change which sim is active. Others have duel active which is better, have a search around on Amazon and Ebay.

Quite a few android phones have duel sim slots for this very reason..But my knowledge is limited as I’ve never needed that feature, but yes it is a thing.

I’m sure someone else can elaborate better.

loads of Android around. What’s your budget?

I have a One Plus 3 which is an excellent phone and dual sim capable.

I have a dual sim android. Most chinese handsets do so.

Im pretty certain it will take calls over both cards.
I have a 3 data sim in one slot and avodafone for calls and SMS in the other.

no switching required, you can specify preference though.

Im pretty certain it will take calls over both cards.

Yes it does 😉

You’ll be wanting to read this
http://www.pcadvisor.co.uk/test-centre/mobile-phone/best-two-sim-phone-20-best-dual-sim-phones-2016-uk-3511526/

My Windows phone has two sims. Both can be used for calls/ text, but only one for data

My Oneplus X takes a second SIM at the expense of the SD card (you can have one or the other, not both as on the OP3 etc) which is the only niggle I have with it.

What I really want is a max 5″ screen (pref. smaller) with dual SIM, plus SD or a decent amount of memory, but I doubt anything like that exists.