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. Sole trader reserve system
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.
Example
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.
Tax bucket
$3,568 7 dollars per 100 receivedGST bucket
$0 0 dollars per 100 receivedSuper bucket
$0 0 dollars per 100 received Guides
Read 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.
Next steps
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.
FAQ
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.