Can you buy a mobile that you can have 2 sims in (occasionally)

[KatyMac]

Or am I stuck with carrying 2 phones sometimes?

Dunno about a mobile but I had a device that held two sims that you put in the sim slot and let you switch between two?

What's a device?

Something like this - dual sim it's not officially supported as you can imagine by most networks and prob won't work if your handset is tied to one network. You may also need to trim your sims to fit as basically it's a small
Metal holder that squashes two sims together to fit into the sim slot. That said I had no trouble using mine when I had it(although you do lose text when you switch between phones).

I bought an ordinary phone & will divert calls from my work mobile after hours

That's what I used it for - even if bog standard you can usually get it unlocked at independent shops

If you google dual sim loads come up try this one www.prepaymania.co.uk/mobilephone/samsung-c5212-dual-sim-fizz-unlocked.html?base

Yes, you can get duel sim mobiles. Check ebay or as Danthe says, prepaymania.

Certainly in the past, depending on what models your phones are, there have been alternative back covers that can hold 2 SIMs and cost 5 to 15 quid.

However, you do need to consider whether messing about with the SIM (trimming them to fit) is worthwhile and also that one phone will need to be unlocked.

Orange has offered "Line 2" in the past where a second number can be used. However, it would depend on

A) whether your contracts have a long time to run (to easily allow you to move the numbers to Orange)

B) whether Orange coverage is adequate where you are

C) whether Orange offers the Line 2 facility at an affordable price

D) whether you would mind changing to Orange and whether they have similar bundles for the same cost

Keeping the accounts separate may be better for clarity over "business costs" and "personal use" and while Orange billing for both and showing "Line 2" info separately (new page) might be OK, paying from one bank account may make this too messy.

That Samsung looks interesting, though do note it is 2G (so if you have any data allowance on existing mobiles, things would be slow if they work at all).

Finally for now, if one of your existing mobiles is on Three, then you would likely lose a number of facilities as most use 2100 MHz for internet and voice, and drop back to lower frequencies if there is no coverage. A Three SIM may not work in the Samsung at all.

Guys - I gave up & bought a nice shiney purple one (that I don't know how to use) but the nice lady in the shop showed me how to divert calls from my old one to my new one

I am happy