Venice Simplon-Orient Express and Exsus Travel were amongst the 15 new companies to join ABTA over the summer.
The Russian National Tourist Office also joined, both as an agent and a principle.
In total, ABTA welcomed 10 new members between July and September, as well as five new partners, including the St Lucia Tourist Board and International Passenger Protection.
ABTA’s membership remains stable at around 1,200, but aggregate member turnover has increased to £38 billion, up from £37 billion last year.
Chief executive Mark Tanzer said: "Recent research has found that ABTA is the most trusted travel scheme in the country, these businesses joining ABTA will benefit from the positive associations with ABTA and its strong brand."
