Space Station Self Storage, which has its headquarters in St Pauls Avenue, Slough, began life as a series of containers by a tip in Colnbrook in 1983.
The company now has five units across the south east, and is giving away England rugby tickets and a commemorative Swatch watch in honour of its birthday.
Space Station customers can submit their memories of 1983 on the company's Facebook page or Twitter until July 31 for a chance to win a 30th anniversary edition Swatch Est 1983 watch.
Customers who submit their early memories of Space Station can win tickets to England v Argentina at Twickenham on November 9. This competition closes on August 31.
The final competition gives creative customers the chance to name the elephant on the company's logo, currently known simply as 'Elephant'. This will run from September 16 and close on November 30.