Problem With Mobile Query.?

[cleoval]

Hi I bought a mobile 2nd hand and the seller says it is on the 3G network.  I have a mobile with a tesco mobile sim but when the sim was transferred to the mobile on 3G it does not work.

 

As you can see I am not tech minded. Does anybody know what I have to do to make the  tesco mobile work please.?  Is it better to take it to one of those mobile shops to sort it out.? Thanks. Happy New Year.

[Buenchico]

You need to be careful not to mix up networks (such as Tesco Mobile, Vodafone and Three) with the different technologies that they use (i.e. 2G, 3G, 4G and 5G).

Assuming that the seller meant that the phone uses 3G technology (rather than the Three network), it could either be 'locked' to a particular network or 'unlocked'.  A 'locked' phone (such as one locked to Vodafone) will only work on that specific network.  An 'unlocked' phone will work on any network.

So it's possible that your 3G phone is locked to a different network and therefore can't be used on Tesco Mobile. Even if it's not though, it can't possibly work on the Tesco Mobile network for very long, as the 3G signal is being switched off next year:
https://www.tescomobile.com/help/device-help/network-and-troubleshooting/network-support/3g

If the seller actually said that the phone is on Three (rather than being a phone that uses 3G technology), that suggests that it's locked to the Three network and, again, can't be used with Tesco Mobile.

Most locked phone can be unlocked (for a fee) though at the type of mobile phone accessory stalls that are often found on markets.

[To help to clarify things here, it would help to know the exact make and model of the phone.  If it turns out to be one using 3G technology, there's not much point spending money on it to get it unlocked, as it won't be very long before the 3G signal is turned off.  If, though, it turns out to be a 4G (or even 5G) phone that's currently locked to the Three network, then it could well be worth the expense of getting it unlocked].