If you have a negative balance it is likely to be the result of a settlement error. Although we endeavour to ensure your bets are settled correctly at all times these errors can sometimes happen. The negative balance could be due to a bet being incorrectly settled as a winner. If you use these funds then your account may show a negative balance once the bet is resettled correctly as a loss.
The negative balance may also be the result of a depositing error. If for whatever reason we do not receive the funds which we have credited to your account, you would see a negative balance as you have been able to bet with funds that aren't rightfully yours to gamble with.
In both instances you would need to deposit to correct the error before you can place any further bets.