Okay, interesting. I'm going to try it.

I just wonder also then, do you know, is there a way that I can perhaps set the iPhone to automatically prepend the phone numbers?

I mean, the second SIM card I'll have will have unlimited calling minutes anyway.

If, for example, I could have it say, if I'm calling via SIM 2, always prepend the phone calls with the DISA number and the commas.

That would actually be amazing.

And then I would just choose the SIM card I want to ring from and it would effectively give SIM 2 the business number without having to mess about a lot.

And then also, could you give me a brief overview of the options for SIM cards I might purchase that actually do act as PBX extensions, especially if I can connect it to my own PBX?