You must have been a citizen of the United Kingdom since birth or a dual British Irish citizen.
You must have resided in the UK for 7 years immediately prior to application.
Your parents/spouse must currently have UK citizenship.
Following the MOD announcement that the UK Armed Forces will now be able to recruit commonwealth citizens without the 5 year residency requirement, please note that the RAF continues to apply standard residency requirements for security clearance, ie, DV employment requires 7-years UK residency immediately prior to enlistment; SC requires 3-years.