Your Immigration Expert
Tier 2 Visa Issued Before April 2010 May Apply For ILR After 5 Years
Those who secured a tier 2 visa before the 6th April 2010 may apply for ILR after five years. Time spent in the UK on Visas granted after that date will not contribute to time served for ILR. In all cases since then, a visa holder must remain in the UK on a Tier 2 visa for 10 years before being able to apply for Indefinite Leave To Remain under the long residency rule.
As your visa has been approved until 2021 you will, in due course be eligible for ILR. Hang in there. Do not forget you will need to pass an English test to secure your ILR visa at that time.