SIM card with data for use in London and Europe

Pick up a sim card from a Three store in the UK (they're everywhere) and this will enable you to use it in France, Spain and Austria for the same rates as in the UK.

yes SIM cards are cheap and available pretty much everywhere.

One thing to consider is your own phone carrier. For the first time last Nov-Dec I turned on my T-mobile unlimited data plan which includes overseas (most all Europe) and included free text message. Worked great. I just used a local SIM for local calls. When I got home I changed plans back to a lower level that meet my US needs. Ill turn it up again for my next trip.

I was doing some research on this myself as I'll be in London and Switzerland later this year. I found a plan on Three that looks interesting. It looks like their advance plans allow data roaming in many countries.

13 GBP for 1GB of data and 600 minutes calls and it looks like unlimited texts. I'm not clear of what data speeds you get when roaming but I'll check when I get there.

http://www.three.co.uk/Store/SIM/Plans_for_phones#?contract=1&data=1&minutes=&type=alltype 1

I've tried a few options, and I used to use my vodafone daily but it really stacked up. I've now done Telestial a couple of times and it ends up cheaper for longer trips and is popular for USA travellers but covers all of Europe. You can check out their Europe roaming Sim Card option here http://www.telestial.com/europe-sim-card they also have explanations there for how their data setup works and can be packaged with an existing phone or unlocked one if you already have one. Hope this helps!

I used an O2 sim card in 2014 for England and Scotland. If I remember correctly, it was 10£ for 500mb (sorry, don't remember the amount of talk & text). In Germany last year they had 02 at a Best Buy type store but I went with Vodafone because the salesman at the store could not verify if we would have service in the Czech Republic and Hungary. Telestial looked expensive to looking at it just now. Who is your provider? O2 is cheaper than using Verizons international coverage.

I used Orange Holiday SIM on my recent trip. The only downside for me was that it's a 14 day card and my trip was 17, so I turned it on after day one and didn't have a plan for my last weekend (had to rely on WiFi). It has a top off option but I'm not sure whether it's to go another 14 days or gives other options?

I only used it in France. It seems to give options for moving from country to country, other than that it might be a little overpriced. I went on the telecabine from Chamonix midi to Hellbruner and got a message about rates in Italy.