It might not pay to be too diligent in filing your tax return in July, with the tax office confirming it has to wait for parliament to pass legislation before it can give people on low and middle incomes a $1000 rebate.
The budget papers last week said a low and middle income tax offset - doubled to $1080 for people earning up to $90,000 - would be included in the ATO's assessment notices after people lodge their tax returns in each of the four financial years it applies.
"This will ensure that taxpayers receive a benefit when they lodge returns from 1 July 2019," the budget papers state.
But senior tax office bureaucrat Andrew Mills told senators on Wednesday the assessments had to be based on the law at the time they were issued - meaning parliament must have passed the increase to the offset amount for people to get it.
It is unlikely parliament will sit between the federal election and the end of the financial year on June 30.
For subsequent years, Mr Mills said if it was clear the policy had bipartisan support, the ATO could include the amount in the tax rate schedules it gives employers telling them how much to withhold from workers' pay.
These schedules are usually issued around the start of each financial year, in June or July.
"It's too late to obviously change schedules (for 2018/19) at this point and, to be frank, I'm not quite sure we have absolute clarity that both sides actually support the exact nature of it," Mr Mills told the estimates committee hearing in Canberra.
"Although there have been indications, we need the absolute clarity that there is identity between what's proposed on one side and what's agreed to on the other."
He denied the process had been chaotic, saying it was just what happens.
"There's no chaos involved in waiting for a law to apply in order to implement something in an assessment."
Mr Mills said the ATO had told Treasury before the budget was released this was the process for giving people the offset.
ATO officials said while Treasurer Josh Frydenberg's office had checked on Monday what they had told a reporter inquiring into the need for legislation, they had otherwise had no contact from Mr Frydenberg, his office or his department regarding the implementation of the policy since budget night.
"Unfortunately, (ATO commissioner Chris) Jordan is actually unavailable to be contacted at the moment - he is on a trek, I can't even tell you where, actually, but anyway we can't contact him by telephone," acting commissioner Jacqui Curtis told the senators.
"But we have checked with his office ... We're pretty certain that he hasn't spoken to Treasury since budget night and certainly none of us have."
