Do you nead a code from Paris to phone the UK?

To place an international call from France, the international access prefix is 00.

The country code for the UK is +44. You must also drop the trunk prefix 0 from the beginning of the UK number. For example, Liverpool's area code 0151 becomes +44 151.

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)