changing phone contract providers

[green_rs13]

Im currently on a Vodafone sim only deal with a Iphone 5S that I bought secondhand (unwanted upgrade) that is locked to Vodafone.

I want to swap over to Tesco mobile on a sim only deal and still keep the same handset and number.

will Vodafone still give me a phone unlock code even though I didn't
get the phone from them?

what order do I have to do it in?
Do I phone Tesco and take out a new contract and then tell Vodafone im leaving and get the phone unlock code / PAC code.

or

do I tell Vodafone that im leaving, get the codes then take out my Tesco contract.

[R3K1355]

Speak to Vodafone first, unlocking iphones properly is a pain in the ass because only the original network can unlock it.
Just stress that you're a vodafone customer, you're out of contract and you want your iphone unlocked.

They might give you the run-around because it wasn't your phone originally, but just ignore them and demand it gets unlocked.

[green_rs13]

I phoned vodafone and told them the deal I was going to switch too, they tried to sell me a different package which was still more expensive so I just lent on them a bit more and they basically matched the Tesco deal so Im staying with Vodafone, as it saves me the agro of switching providers.