Looking for unlimited Internet sim?

I have an iPhone and I want to go with a phone company that will offer unlimited Internet cause I work from home however for the next month I will be moving a lot. So I need a phone company where I can attach my phone to my computer to get Internet and it needs to be completely unlimited cause I use up a lot. I'm in the uk by the way.

You are asking 2 different questions

1 - unlimited internet (that is Phone use only)

2 - Wireless tethering (off the phone use)

(truely) Unlimited internet plans are available from
t-mobile (full monty)
Three (ultimate plans and the One Plan)

Tethering:
as of Aug 8th, t-mobile removed tethering from the Full Monty.
you have add a bolt-on to do it (same as other plans)

only the One Plan offers wireless tethering on their plan
the Ultimate plans are Phone use only + tethering bolt ons.

O2 allows tethering on all their Contract plans
but their idea of Unlimited (like Orange) is 3GB and usually the plan is 1 or 2GB only

So you only have 1 choice really.

If you want a contract sim card then I'd suggest 'Three' but depends if they'll have good network to where ever you are traveling.

If you want a pay as you go sim card then I'd suggest Giffgaff, they give unlimited internet, 300 mins and unlimited texts all for £10 a month but you have to buy a bundle for £10.

I use three, they have quite a good mobile internet network. Very fast.