There are no continuous residence requirements associated with the extension of stay for Tier 1 General migrants. You still need to meet financial requirements of the immigration rules, but you can rely on earnings from abroad. At the same time it is important to remember that an application for extension of stay as a Tier 1 General migrant can only be made before 6 April 2015. After that date Tier 1 General migrants will only be apply for settlement or variation of status. You may not qualify for indefinite leave to remain when your extended visa runs to an end, as you would need to demonstrate continuous residence of five years. Bear this in mind before you decide to apply for extension.