More betting operators have signed up to British Racing's Authorised Betting Partner (ABP) scheme.
188BET, BetStars, McBookie, SeanieMac and ApolloBet have all joined in recent days, agreeing to make a "suitable level" of voluntary contributions to the sport based on their British racing business.
Agreements have already been reached with Betfair, Bet365, 32Red, Sky Betting & Gaming and Bet Victor.
British Racing’s Authorised Betting Partner (ABP) is a voluntary scheme that aims to reward betting operators who commit to making a contribution on their betting activity to fund British racing.
ABPs have agreed to make quarterly contributions to the Levy Board for three years, subject to the implementation of the Horserace Betting Levy replacement.
The UK government has committed to replacing the Levy mechanism by April 2017.
In return for their commitments, ABPs receive a kitemark and other benefits from British Racing, including access to key sponsorships, media opportunities and customer data.
Nick Rust, Chief Executive of the British Horseracing Authority (BHA), said: “British racing provides an important product to betting and gaming operators and we are delighted our ABPs recognise the value of a partnership with British Racing.
"People who bet on British racing deliver substantial value to betting and gaming operators over and above the gross win generated on racing.
"We look forward to working with all ABPs to help them take the opportunity to gain significant exposure to British racing’s customers."