Suppose a shareholder is resident in Dubai a tax free country and a UK company pays him/her a dividend.
The whole dividend amount is tax free.
HMRC link: https://www.gov.uk/hmrc-internal-manuals/savings-and-investment-manual/saim1170
HMRC Help-sheet HS300 is also helpful.
https://www.gov.uk/government/publications/non-residents-and-investment-income-hs300-self-assessment-helpsheet/hs300-non-residents-and-investment-income-2015
Another good article on taxation.co.uk https://www.taxation.co.uk/Articles/2016/05/31/334836/readers-forum-barnstorming
Taxation in action: https://www.theguardian.com/business/2005/oct/21/executivesalaries.executivepay