Am I obligated to provide a "Letter of Invitation" for foreign visitors?

No. WWOOFers are responsible for arranging their own travel requirements. If traveling from another country, this means securing their own visas and travel documents. Hosts are not required to assist a WWOOFer with any documentation for their visa applications, and WWOOFers are encouraged to secure their visas before joining as a member.

If you are asked about providing a letter or other documentation, please direct WWOOFers to the visa information.