Since 6 April 2015, applications to extend leave to remain on the basis of Tier 1 (General) are no longer being accepted. The theory is that most current holders will be due to apply for indefinite leave to remain at the end of their current visa. Applications for indefinite leave to remain will no longer be accepted after 5 April 2018. Those who require an extension of their existing Tier 1 (General) leave to remain before being eligible for indefinite leave to remain ought to have applied to the Home Office for an extension of their leave before 6 April 2015.
Find out more about Tier 1 (General).