I honestly dread my 26th birthday purely because I'll no longer be able to get as many cheap theatre tickets as I currently do. There are so many schemes around for young people, you just have to know about them. The majority of these are based in London theatres but it's always worth checking out if your local theatre has any young person deals. 

Entry pass is the scheme I use the most. It's free to join, you just have to be 16-25 and living in the UK. Members can get tickets for £5 and bring a friend (also under 25) for £7.50. The majority of the time the tickets are in the front 3 rows of the stalls so it's incredible value for money. Other perks include workshops and events (I went to one about the set design in Medea and had a fantastic time) and discounts at the bookshop, cafes, costume and prop hire and backstage tours. There's only a few entry pass seats at every performance so I recommend keeping an eye out for the season booking dates for entry pass and booking as soon as they're released.

The RSC Key is another free to join scheme that gives you £5 tickets to any of the Royal Shakespeare Company's shows in Stratford-Upon-Avon and London as well as a host of extras. You just have to be between 16 and 25 to sign up. Extra discounts include a number of West Midlands attractions and a loyalty card that allows your 6 RSC show to be free.

If you're wanting to see Matilda in London, 16 tickets for every performance are available from the box office for £5 for 16-25 year olds. The box office opens at 10am but prepare to queue for a few hours as they are in hot demand.

Young Barbican gives 14-25 year olds discounts on not just theatre but art, film, music and dance as well. They have tickets ranging from £5 to £15 and allow you to bring a friend for the same price. Like many of the others, some tickets sell out fast so be sure to keep an eye on your email for when tickets are available.

Mousetrap Theatre Projects are a theatre education charity  who aim to help young people see theatre. They have two schemes, theatrelive4£5 for 15-18 year olds, and westend4£10 which is for 19-23 year olds or full time performing arts students. Each month they organise at least one theatre trip (£5/£10) which includes a pre/post show talk with the cast and creatives. They also from time to time have free tickets to give away so it's well worth being on their mailing list. It was at one of these free events that I ended up being pulled on stage by James McAvoy which was possibly my most surreal theatre trip to date.

Membership to the Open Air Theatre, Regent's Park's Breeze scheme costs £10 a year and gets you access to £10 tickets during previews as well as 10% off the Bar and BBQ at any Breeze events and previews. Open during the summer months, the Open Air Theatre is a magical theatre experience and worth it for the atmosphere alone.

The Old Vic's current scheme, PwC under 25 Club, requires no sign up. All you have to do is enter the promo code PWC CLUB or quote it over the  phone when booking and you have your choice of 100 seats each performance priced at £12. Just don't forget your ID when collecting from the box office. Come September 2015 PwC under 25 Club is changing to PwC Previews. Half of all tickets for the first 5 previews of every show will be priced at £10 and released 5 weeks in advance.

The Young Vic offers £10 tickets for under 25s, you just have to select them when booking and remember to bring proof of age when collect them from the box office.

My final tip isn't a discount ticket scheme but it's good to know. Before booking any tickets at a theatre I'm not familiar with I always check out the seating plans on theatremonkey.com. They have colour coded seating plans with information about where all the best value seats are and reviews from theatre goers of the view and comfort levels of those seats. It's a great way to see if you really are getting a bargain or if you'll be stuck in the Gods, behind a pillar, with your knees under your chin.