Use this option if you want your unmatched bets to be automatically cancelled after the number of seconds indicated in the option.

​

If the option is set to zero seconds the bet will be cancelled straight away if it is not immediately matched.

​

If the bet gets partially matched then the remainder is cancelled.

 

The API itself has a Fill or Kill setting but only works where you are using zero seconds and stake meets the Betfair minimum amount.

​