All members of the armed forces and MOD employees can save up to 15% on Vodafone monthly contracts.
For everyone else:
Once you are on a Vodafone plan you too can create your own refer a friend link via the referral scheme. You can earn £25 Amazon gift cards for each friend that you refer.
This offer is only valid instead of the Armed Forces Vodafone Employee Advantage Scheme which is only valid for military personell.
For full terms and conditions please see Vodafone official site