You can, with a steady hand trim some sims. Sim -> Micro -> Nano (depending on your layout of your sim)
e.g.
http://www.amazon.com/QQ-Tech-Cutter-Standard-iPhone-Adapters/dp/B009P16FKY
http://www.amazon.com/Noosy-Micro-Cutter-Converter-adapters/dp/B003UEWF8I
You can get Adapters (with varying degrees of success) to convert Nano->Micro->Slim to use a given sim in a different sized holder / slot ...
Or like much of the (Non US) world ... Use a Dual Sim Phone ... ( e.g. keep your business number + personal number separate )
http://www.pcadvisor.co.uk/test-centre/mobile-phone/3511526/best-dual-sim-smartphones-2014/
http://www.cnet.com/news/why-you-want-a-dual-sim-phone/
http://www.phonearena.com/news/The-best-dual-SIM-phones_id32596
If you want to use your phone, as a phone, you know, for calls + texts ...
Or use google voice , as a "virtual" phone / number / font end / - so you can change the physical phone back end at will - without having to inform your contacts - assuming you gave them the google voice number first.