Build a tax reserve rule you can use the moment a payment lands
Buffer is for one job: turn a realistic income pattern into a simple reserve rule for tax, GST, and optional super. Use the calculator first, then read the supporting guides only if you need more context.
A compact example of the reserve rule
Example only: a sole trader receiving a typical payment of $4,500 each monthly, with $18,000 in annual business expenses under the current GST-credit and super settings.
Estimated rule
Set aside 7 dollars out of every 100 received About $297 per typical payment, with roughly $2,703 left after reserves and annual expenses.Tax bucket
$3,568 7 dollars per 100 receivedGST bucket
$0 0 dollars per 100 receivedSuper bucket
$0 0 dollars per 100 receivedRead only the supporting context you actually need
The calculator should be first. These guides exist for the questions that usually come right after the reserve rule is set.
How much tax to set aside
Use this when you want the reasoning behind the reserve percentage, not just the output.
How to create a tax buffer
Turn the reserve rule into an actual operating habit, account structure, and review rhythm.
Why separate GST from income
Use this when the main confusion is whether GST belongs in spendable cash or its own bucket.
Move from reserve rule to the next tool in the workflow
After the reserve rule, the next job is usually BAS detail, annual modelling, due dates, or invoicing.
Choose the next tool by the decision you are making
Use one of these short routes if the reserve rule is clear but the next operational question still is not.
I need the reserve rule now
Go straight to the calculator when the question is still how much to set aside from each payment.
I need BAS detail next
Switch to BAS once the reserve habit is set and the job becomes GST or PAYG statement detail.
I need due dates next
Open the calendar when timing is the blocker and you need to line the reserve rule up with obligations.
Questions this app is designed to answer quickly
Is this a bookkeeping system?
No. It is a reserve-rule app. The point is to create a simple habit for each typical payment pattern, not a full ledger.
Why show dollars per 100 received?
A ratio is easier to apply in real life than a yearly estimate when money hits the account.
Will super always reduce the tax estimate?
No. The calculator only treats personal super as deductible when you choose that setting, and the estimate assumes you will meet the ATO deduction conditions.
Can I share a setup with my accountant?
Yes. The calculator stores state in the URL so the same assumptions can be shared directly.