International Dialing Code for Guadeloupe is +590.

Internet service is available through a local server, Caribsurf, run by the phone company. Internet Access is available at all hotels on Guadeloupe, and at several other locations:

Cell phone coverage is available everywhere on Guadeloupe, but check with your cellular service provider to be sure they offer international coverage and that your cell phone supports service from the Caribbean – you’ll also want to be aware of your carrier’s rates as calls from Guadeloupe (or to you while you are on Guadeloupe) may very likely be at a higher rate. Alternatively Guadeloupe GSM prepaid international cell phone service; prepaid phone cards; cell phone calling cards; low cost, high-quality special dialling services such as toll free dial around to Guadeloupe with free minutes and no fees.

Digicel update December 2014:

Anyone cruising using Digicel should be aware that if you purchase a SIM card in one country, it cannot be topped up in a different one, as previously possible. So if you wish to use the sim bought here while cruising in other countries, you should either put on a large enough sum to cover your needs, or set up an account and do it online.

You can top-up Digicel at https://online-top-up.digicelgroup.com/