Can you unlock a iPhone 6for free?

Can you unlock a iPhone 6for free?

No, not unless you have an unlocking cable, which is about £4/$6.50, you could take it to a shop which is probably £10/$14

My personal choice, buy an unlock code for about £3/$5, its the fastest and cheapest way, just pop in the new SIM and it will be unlocked to any network.

I assume you mean unlock it to use a SIM from any network?