The Pony Club wants to hear from all A test holders for a reunion being held this summer.
Any members past or present who hold the prestigious test are being encouraged to attend.
Records show over 1,500 people have passed the test but many of their contact details are no longer available.
“The A test reunion is a chance for this exclusive group of equestrians to reminisce and celebrate friends, new and old,” said Jenny Cowen, the Pony Club’s training officer.
“We really hope to be able to get in contact with as many as possible to attend both the gala dinner as well as the daytime event so we can celebrate in style,” she added.
It is hoped that the A test holders could help drive the PC’s training ethos of all-round horsemanship and care forward in future.
The gala dinner is being held at the Best Western Buckingham hotel on 22 June. The guest speaker is coach William Micklem, one of few to have passed his A test with honours.
The A test celebrations continue at a training day held at Addington Manor the following day hosted by four-time Olympian Richard Davison and international coach, John Ledingham.
The pair will be running a series of riding sessions to celebrate the Pony Club’s highest accolade.
The event is hoped to be an opportunity for A test holders to network and share their experiences from the equestrian industry and beyond.
The dinner costs £25 to include an arrival drink, three course meal and speaker.
The A test celebration at Addington Manor costs £15 to include lunch.
Tickets to both events can be bought for £38.50; to book visit www.pcuk.org/training