I just learned (the hard way) that there are actually lots of countries Willhill doesn't accept.

Australia
Belgium
Bulgaria
Cuba
Cyprus
Denmark
Estonia
France
French Guyana
Greece
Guadeloupe
Hong Kong
Iran
Israel
Libya
Martinique
Myanmar
North Korea
Norway
Philippines
Réunion
Sudan
Syria
Turkey
United Arab Emirates
USA

For the eligible players, this obviously means an even smaller field, so good luck!