UKH

Got a Samsung Galaxy S5 which I'm looking to sell / donate.

I phoned my mobile provider, Vodafone, to check if it's locked and I got an unlock code. Seems I need to insert a non-Vodafone SIM, turn phone on and enter the code.

However I do not have a non-Vodafone SIM. Can it be unlocked in another way?

You could just buy the cheapest non-Vodafone payg sim you can find in the supermarket?

A Tesco Pay as you go sim costs 99p

That's cheap but I'm looking to sell or donate, not incur any costs!

An ASDA PAYG SIM is free if you order online apparently 

https://mobile.asda.com/pay-as-you-go

Wow, seems like £1 to unlock it could be added to the price or at least is a better bargaining point than a phone locked to one carrier.

Borrow a sim from a friend?

Can you borrow a friend's SIM for the few minutes that are required?

Agreed! 

An alternative, if you don’t wish to temporarily borrow or otherwise use another sim, could be to write the unlock code on a bit of paper and stick it to the phone for the new owner to use? I’m not aware there is a time limit on using the unlock code (at least in the past there wasn’t as it was connected to the unique IMEI number). You can advise that you have the unlock code for the phone when you advertise/donate.

In fact I will donate the £1 to the OP if they contact me 

No. There's a principle involved!

I’ll donate an extra £1 to MRT