if you have a tax debt, your ftb reconcilliation result can be used by the ATO to repay some or all of the debt. you will receive a letter with the outcome. it generally takes a short ish period of time (a few days turnaround) but if you have a debt with ATO or FAO, there is a process that transfers credit with one department to cover debt with the other - and it can take up to 4 weeks for an outcome.