mobile for tethering

I want to use a 4g data sim in a smartphone, with which i will be tethering my other phone to give me internet access.

Do i need a 4g phone, or will it not matter as i will be using the tethered one which has 4g? or does it not work like that?

As both phones will be together is there anything i should be looking for when looking for the other smartphone. I'm hoping cheap and cheerful will do the trick.

The phone using 4g sim needs to be 4g/lte capable to use 4g otherwise you will only get 3G.

Thanks, will look for 4g cheapy then

Could you not just use the 4G capable one to tether/connect too...
If it's network locked to another sim just go on fleabay and get a unlock code..
Will be cheaper than a new phone.

If you are tethering then it should connect via wifi hotspot rather than through the SIM - it shouldn't matter whether you are using an old phone or new phone as long as you have a decent wifi unit inside it.