Members of Air Berlin's Topbonus loyalty programme can collect double award miles from an accrual partner until April 30.
To be eligible, members need to select a single preferred partner from the 22 available and register at airberlin.com/preferredpartner.
Once registered, double miles will be awarded for every purchase made through the chosen partner during the promotion period.
Anyone not yet a Topbonus member can sign up for free online and immediately choose their preferred partner and participate in the offer.
The 22 accrual partners taking part in the offer include hotels, car rental companies, tour operators, airport duty free shops and a hotel rating portal.
Graham Smith
