Form CA3837, Self-Employed, Temporarily Working in Another Country Within the European Economic Area, is an official statement prepared by self-employed individuals who are planning a temporary move abroad. If planning to work in a foreign country within the European Economic Area, the form is necessary to figure out which country's legislation will be applied to your social security.
This form was issued by United Kingdom HM Revenue & Customs and was last revised on February 1, 2020. A printable CA3837 Form can be downloaded through the link below for reference. The actual form can only be only filed online on the official website of the government of the United Kingdom.
Here is how to fill out Form CA3837: