It's part of an odd compromise with the private-sector media companies and government reached a few years ago. Within the UK, the BBC is only allowed to show co

It's part of an odd compromise with the private-sector media companies and government reached a few years ago. Within the UK, the BBC is only allowed to show content that is wholly funded by the license fee, and cannot solicit advertising or other external funding for the content. This was insisted on by the private-sector media companies, who don't want the BBC competing with them in the commercial portion of the market. Separately, the BBC overseas service is required to solicit external funding for its content, and not to cross-subsidize it with the license fee. This was insisted on by the government, which did not want license-fee revenues subsidizing international content, but still did want international content to exist as part of the UK's global cultural export/image. But due to the previous agreement this content then can't be shown in the UK, because it's commercially-funded content.