London's only official half price ticket seller, the tkts booth in Leicester Square, celebrated its 30th birthday yesterday (10 August 2010) giving away tickets to the first 30 people in line and launching a scratchcard giving theatregoers the chance to win free tickets.

To celebrate the birthday, tkts were joined outside the booth by cast members from a number of West End shows including Matthew Goodgame and Over the Rainbow contestant Lauren Samuels from the cast of Grease; Jacqui Sanchez, Sam Harrison and Alan Pearson of Avenue Q; and David Bark Jones, Dianne Pilkington and Timothy Speyer from the cast of The 39 Steps.

When the booth opened back in 1980 the West End offering looked slightly different with Evita, Annie and Jesus Christ Superstar the hit shows of the day. However some London theatre institutions were already in place with The Mousetrap having opened in 1952 and Cameron Mackintosh's first revival of Oliver! in full swing at what is now the Noel Coward Theatre.

The original ‘Half Price Ticket Booth’ was a small, wooden hut painted in green and yellow stripes which stood on the west side of Leicester Square. When the square was reopened by the Queen in 1992, following the installation of an electricity substation under the garden, tkts was welcomed to its new home in the Clocktower Building by the Mayor of Westminster. The booth changed its name to 'tkts' in 2001, adopting the name of its Broadway counterpart.

In the past 30 years, tkts has sold a staggering 10.9 million tickets to more than 1,200 shows, and is responsible for 1 in 39 theatre tickets sold in the West End. Also impressive are the booth's recent sales figures, which have seen a nine percent increase in year-on-year sales for the five months to May 2010.

Although known as the 'Half Price Ticket Booth', the service, which is run by the Society of London Theatre on behalf of West End producers, sells tickets at a range of discounts, up to 50% off. Tickets are available on both the day of the performance and up to a week in advance. Scratchcards to win free tickets are available at the booth until the end of the day today (11 August 2010).