Strangely, I had the opposite experience with EE in London. It barely worked at all in many locations, including outside the Orange store on the King's Road (they had a booster in-store so it worked there). No more EE for me - I've found 3 to be much more reliable.

Three / 3 / Hutchison network in the UK recently revised their pricing for PAYG and plans.

Calls within the UK on PAYG are now 3p flat rate. Key: PAYG topups do not expire each month or threemonths anymore. So none of your money is wasted and you get the best call rate for calls outside of bundles or plans. They can also give you dialling codes that make many international calls 3p per minute, or other low rates, to call other countries from the UK with your same Three PAYG SIM. Phone Three 3333 free from your Three SIM to get the codes.

Next best I have found is GiffGaff. Excellent 'bundles' of a certain number of minutes for a fixed amount that you pay upfront, if you want to make lots of calls. BUT the bundles expire after 1 month. Outside of bundles their call rate can now be beaten (including by Three above).

Tesco is apparently not bad.

Tesco and GiffGaff are MVNO's currently running on O2 network.

IMHO Three currently has the best price performance for data too. Some defects in coverage, and some current network issues which I am sure will be fixed very quickly. Note Three allows Skype, most other mobile networks in UK block this. For performance TMobile/EE/Everything Everywhere is pretty good most places, but requires you to buy bundles that expire.

Just my view of the current best options in the UK market, from someone who has watched it for many years.

Just got back from a week in London. I used giffgaff and was pretty happy with it.

I ordered a SIM from one of the agents rather than directly from giffgaff and that got me an additional £5 when I topped up. I found lots of links to agents that will send out SIM cards at no charge.

The SIM was shipped to my US address so I had it before I left. Activated it online with no issues and added £10 using my US credit card. I think I put in a UK postal code for my ZIP and it went through just fine. The extra £5 showed up immediately and then I converted the £10 top up to a £10 goodybag which gave me 500 UK minutes, unlimited UK texts, and 1GB of data. This was really more than I needed but wasn't sure how much data I would use.

The nice thing about the extra £5 was that calls to the US were just 3p a minute so I didn't need to worry about using Skype, etc.

Giffgaff also has a app that lets you see how many minutes, etc that you've used.

Didn't really look at how this would have worked if I had been traveling in Europe but if you are just in London then I would definitely recommend this.

Forgive the obvious newbie question. I couldn't find the answer searching the thread. I'm looking to get a SIM for our iPhone 3G or 4S (depends if AT&T will let us unlock the 4S before we go). We are most interested in using for data and some texts for the 2 weeks we will be in the UK. The Three plans look like the least expensive for unlimited data. Do we just walk into a store and buy a SIM? Online the Three site says that you need to give 30 days notice to cancel even for the 1 month prepaid plan? Am I reading too much into this?

We are flying into Gatwick, taking the train to Victoria Station and then the tube to Earls Court. I'm looking for a Three store anywhere those locations and the nearest ones are over 1-2 km away. Are there third party stores selling the SIMS and do I need to worry about them being sketchy?

Thanks for the help.

That's for a postpaid plan. YOu want prepaid. You can buy a SIM in vending machines at Heathrow (and Gatwick too, I think) or at any Carphone Warehouse or Boots pharmacy. Buy a top-up card for the amount you want for the plan, then call the number on the top-up card to choose the unlimited data/texts plan you want. It's very easy.

Check out Giffgaff - I posted about them in this thread earlier. You'll have your card activated and UK number all setup before you leave the US.

My sole problem with Giffgaff is that I'm not sure which SIM card I'll need. If I get the 4S unlocked, it will be a different card from if I end up having to use the 3GS.

Get the biggest option. The only difference in SIM card types is the amount of plastic around the chip. You can buy a cutter for a few dollars on Amazon.com.

Nano-sized SIMs are thinner as well as smaller. The SIM cutter I got comes with a little square of sandpaper to take care of that problem.

There's a Carphone Warehouse very close to the exit of Earl's Court station who will sell you a SIM of whatever variety you need and usually the staff are good about putting it into the phone and getting it working.

I'm on 3 and find it to be excellent - and I live near there. Personally I'd go with 3 over GiffGaff because you have proper support options - 3 stores, Carphone Warehouses and support numbers that are properly staffed. I'm sure Giff Gaff are ok but, as a virtual operator rather than a network, it's simply higher risk. You are on a network rather than a virtual operator at home presumably for similar reasons.

Sanding off a SIM card has always seemed sketchy at best to me.

It's just removing a smidge of plastic.

Has anybody had any success recently with ordering a sim card from toggle mobile? I keep getting a "payment error" message when using a US address an credit card.

Why not just order both? Once you know which phone you'll be using, only activate the sim card for that one.

Toggle's customer service is a little uneven (to put it charitably). You should be able to complete your order if you choose PayPal for the payment method -- at least, that works for top-ups. You don't have to use a PayPal account, you can just use PayPal's credit-card payment system.

I see they've increased the minimum starting credit to £25, which seems like a lot to me. I bought two Toggle SIMs from the eBay vendor gosimcard with just £5 credit for less than $15 each (though I see that vendor has raised the price a little). They arrived promptly, cut to the size I requested. I had to top up one of them twice at ten pounds+significant aggravation, so that one would have been cheaper direct from Toggle. The other one still has a little less than two pounds' credit on it after a week in France and three weeks in the UK.

-Andy

Thanks Andy. Unfortunately PayPal is not showing as an option for me on the order page. I've sent an email to customer support, but if I don't hear back soon, I'll go the ebay route. It looks like cost will be practically the same - $7 is just under the 5gbp that toggle charges on their website. Top ups start at 20gbp too so I'll be paying roughly 25gbp either way.

Were you happy with their voice coverage in the UK? I'll mainly be in central London.

They use the O2 network in the UK. My coverage was fine in London.

You may be looking at a different offer from gosimcard. The one I see is US$17 for a card with £5 on it.