With effect from Thursday 13 November, entry clearance will become mandatory for nationals of the ten phase one countries and all work permit holders (except for nine EU accession countries) who wish to stay in the UK for more than six months.
Nationals of Australia, Canada, Hong Kong (SAR passports), Japan, Malaysia, New Zealand, Singapore, South Africa, South Korea and the USA will require entry clearance before travelling for all stays in the UK of longer than six months.
The entry clearance requirement will also apply to all work permit holders staying for more than six months, with the exception of the nine non-visa national EU accession countries (Cyprus, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland and Slovenia).
For more information, see: UK Visas