The obvious answer is you haven't paid enough tax. Perhaps your employer isn't withholding quite enough tax from your pay?
If that turns out to be the answer, and your total owed is around $1k, I wouldn't personally correct that with my employer. I'd prefer to have the use of that $1k throughout the year and pay the ATO what I owed at the end.
The low-middle income earner offset is gone this year so I imagine there will be quite a few people not getting as much back.
Doesn’t explain owing money though.
Just to note, you can set up a repayment plan fairly easily. Just call up the ATO and state how much your comfortable with paying back, divide it up to end roughly same time next year. Minimises the bill shock.
My husband is a tax consultant. This week he had a client who receives a pension alongside some casual work. The employer didn't consider the pension and withheld tax according to a lower tax bracket than she should have been in, considering both.
She owes nearly $5k. Hubby says "this employer is large and experienced, they absolutely should have known better". Poor woman.
Anyway, it's worth checking that your tax withheld from your paycheck is correct. If they aren't taking enough out, you'll have a balance to pay at tax time.
You should be able to compare the items with your previous tax return.
Did you get a bit of money in interest from savings?
Yes but only a bit over $100.
If you have a HECS debt, it may be due to the fresh increase to indexation
Indexation doesn't affect how much HECS you owe per year though, only the lifetime total balance.