Tax prep support
Estimated tax payment support
We calculate and schedule your PAYG instalments from reconciled books, so quarterly instalment notices line up with what your business actually earned, not a flat estimate the ATO carried forward from last year. Your TPB-registered agent reviews the position before any adjustment goes in, once a written supervision agreement with us is signed.
Tax working papers
Illustrative client · August 2026
AUD
- Year-end books closed and reconciledDone
- Fixed asset and depreciation scheduleDone
- Book-to-tax adjustments listedDone
- Supporting schedules for the preparerIn progress
- Handed to the signer for review and filingNext
Illustrative. An example of the document, not a client's figures.
Instalments that track the year you are actually having
PAYG instalments are meant to pre-pay tax on business and investment income across the financial year (1 July to 30 June), based on either the amount the ATO calculates or a rate applied to your actual instalment income. When a business has a stronger or weaker year than the prior one, the default instalment can badly overshoot or undershoot the real liability.
What we do with it
We watch your reconciled income each quarter and calculate whether the instalment on file still fits, or whether a variation is worth discussing with your appointed tax agent before the next instalment falls due. That keeps cash tied up in instalments closer to the amount actually owed, rather than sitting with the ATO as a large refund or arriving as a shortfall at year-end.
Company tax rate context
Because a base rate entity's company tax rate is 25% against the standard 30% rate, getting that classification right at the start of the year changes the instalment maths from the first quarter, not just at return time.
Where the numbers come from
Every instalment calculation starts from the same reconciled bookkeeping and monthly reporting Finbryn already produces, so the figures used for instalment planning match the figures your eventual return will use, instead of two separate estimates drifting apart over the year.
Record-keeping behind the variation
If you vary an instalment down and the final liability comes in materially higher, the ATO can apply a general interest charge on the shortfall, so a variation needs a documented reason, not a guess. We keep a short note of the reconciled figures and the reasoning behind each variation alongside the quarterly workpapers, so the position is easy to defend if the ATO asks later. That same file also makes the year-end return faster to prepare, since the instalment history and the return draw on one set of numbers rather than two.
Questions
Frequently asked questions: Estimated tax payment support
Do you lodge the PAYG instalment variation for us?
We calculate and prepare the variation figures. Once your TPB-registered agent has signed a written supervision agreement with us, that agent reviews and lodges the change with the ATO.
How often do you review our instalment amount?
Each quarter, alongside your regular reconciled reporting, so a variation is caught before the next instalment notice is due.
Why does the company tax rate matter for instalments?
A base rate entity pays 25% company tax against the standard 30% rate, and that difference changes what a correctly sized instalment looks like from the first quarter.
Who lodges the PAYG instalment variation if the estimate changes?
Your registered agent does. We prepare the recalculated estimate and the supporting reasoning; the variation itself is lodged with the ATO under your agent's registration.
What software do you use to calculate the estimate?
Your existing bookkeeping file plus prior lodged figures, run through a standard PAYG instalment calculation your registered agent reviews before any variation is lodged.
How do you calculate the estimate?
We project the year from actual results to date and check the number against a safe-harbor based on last year's liability, whichever protects you better.
What if income changes a lot during the year?
We revisit the projection through the year rather than setting it once at the start.
Who reviews the work before it reaches us?
Every deliverable under estimated tax payment support is reviewed by a senior principal before it reaches you. You keep access to the underlying file at every stage, so nothing about the work happens somewhere you cannot see it.
What is included in estimated tax payment support?
Estimated tax payment support covers quarterly income projection built from current-year books and estimated payment calculation for each due date. The exact scope is agreed and set out in writing before work starts, so you know precisely what is and is not covered before the first deliverable arrives.
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Next step
Talk to the team that would run your books
A short call covers your setup, your software and what a first month would look like. You get a written scope and price after it.