A US-bought Tomtom worked fine for me in Spain and the Netherlands. For data starting out in the UK, see CarPhoneWarehouse prepaid sim-only.

Starting out in UK? will this work outside of UK?

Well Huss, Gatwick is the first place listed on your itinerary in your signature line — under your title “Euro Trip — I am leaving from Toronto ….” You have to buy it somewhere, and since that’s the first place listed, since I knew about Carphonewarehouse and their prepaid sim call and data chart, I thought it might be helpful for you — since that’s what your question was about. Are you following me?

It should work outside of the UK — as long as you choose a provider that publishes roaming rates for the countries in which you intend to use the sim. You will need to check the handy-dandy chart link that I made for you to find the rates—or link to the international call and data roaming rates—for each provider.

I think it would be better to buy a Sim card in Europe to avoid any roaming charges and better reception. Though I can’t help you for exact data charges but have consulted one of my friends who has been there. He said the data cost is not that high there, so I think you won’t find it expensive using GPS, etc.

Hope it helps.

Purchase local prepaid sim is a great idea, but do keep in mind that every time you cross a border in Europe, you are roaming. All “Europe” is not on the same provider tariff.

For example, if you have a UK prepaid sim for voice and/or data, when you leave the UK, you will be roaming at much higher rates (with great variance among providers, so shop around based on your travel plans). This assumes that your provider does indeed roam with another provider in the next country. Do not assume that just because it’s Vodaphone or Lebara or Orange that it automatically roams to those networks in the next country — not always.

If the sim you’re considering does not list data rates for the countries which you wish to roam with data, for example, then it’s usually safe to assume that particular prepaid sim does not yet offer roaming data for those places.