How often to do your bookkeeping: a weekly, monthly and quarterly rhythm for sole traders
The honest answer to how often is: more often than once a year, and less often than you fear. Bookkeeping done in small regular sessions is a few minutes at a time; done in one session in June it is a lost weekend and a list of expenses you cannot remember. This guide lays out a rhythm that fits around actual work, what each session involves, and what to do if you are already behind.
Updated 16 September 2026. General information only, not tax advice.
Weekly: ten minutes
- Send invoices for work finished this week. The day you finish is the day the client is most likely to pay promptly.
- Photograph receipts from the week and attach them to the transaction, or drop them in one folder. Paper fades and gets lost; a photo on the day does not.
- Glance at unpaid invoices. Anything past its due date gets a reminder. Software does this automatically; FlowFi sends the reminder and shows the overdue list in your weekly summary.
If you take cash, record it this week too. That is the whole weekly job.
Monthly: twenty minutes
This is the session that matters.
- Upload the bank statement for the month (CSV or PDF from your bank; see how to export a bank statement).
- Review the categories. With AI categorisation most lines are already right; check the ones flagged for review and correct any that are wrong. Each correction improves next month.
- Reconcile. Confirm everything is categorised, mark paid invoices as paid, add anything paid from a personal card.
- Check GST, if registered: glance at the running G1, 1A and 1B for the quarter so the BAS holds no surprises.
- Move the tax money. Transfer the GST and income tax set-aside for the month to a separate account.
- Log working-from-home hours and business trips for the month, if you have not been doing it as you go.
Do it on the same day each month; the first business day after the statement is available is the natural one.
Quarterly: the BAS
If the monthly sessions have happened, the BAS is a review: open the quarter’s figures, check that the three months look complete, confirm the labels, lodge in ATO online services and pay. Half an hour, most of it double-checking. Due 28 October, 28 February, 28 April and 28 July; see BAS due dates.
The quarter is also a good time to look at the numbers as a business owner: income by month, biggest expenses, unpaid invoices, and whether the tax set-aside is on track. A cash-flow forecast, which FlowFi builds from your invoices and history, tells you whether the next quarter’s bills are covered.
Annually: year end
With monthly bookkeeping done, the year-end job is assembling the pack for your accountant or your own return: the categorised income and expenses, equipment purchases, vehicle logbook percentage, home office hours, super contributions with the notice of intent, PAYG instalments paid, and the four BAS. See what to give your accountant and the end of financial year checklist. In late June, look at whether a planned purchase or super contribution should happen before the 30th.
Why monthly is the floor
Below monthly, three things go wrong. Receipts disappear, so deductions are lost. The GST position is unknown until the BAS is nearly due, so the payment is a shock. And transactions become unidentifiable: a $140 charge from an abbreviated merchant name is obvious in the week it happened and a mystery in June. The ATO also expects records to be kept as you go, and a year reconstructed from memory is not that. Monthly keeps every one of those problems small.
If you are behind
Do not try to do the year in one sitting. Work in months: download each month’s statement, upload it, review the categories, move on. With software doing the categorisation, a month takes about the same twenty minutes it would have taken at the time, so a year behind is roughly four hours, not a weekend. Start with the oldest quarter that has an unlodged BAS, if any; see missed a BAS. Receipts you cannot find are the main loss; bank statement lines are acceptable evidence for small amounts, so not everything is gone.
Making the rhythm stick
Put the monthly session in the calendar as a repeating appointment, keep it short enough that you never dread it, and let the software carry the load. FlowFi emails you when an uploaded statement has been categorised and what needs a look, sends a weekly summary on Monday with the money in, money out and anything overdue, and reminds you seven days and two days before each BAS. The rhythm then runs itself; you just show up for twenty minutes.
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Frequently asked questions
Is it worth doing bookkeeping weekly instead of monthly?
For invoices and receipts, yes, because they are easiest in the moment. For the statement review, monthly is enough for most sole traders, because that is how often the bank statement arrives.
Can I just give my accountant a shoebox once a year?
You can, and they will charge for the hours it takes to sort it, and you will lose deductions for the receipts that are missing. Monthly bookkeeping in software costs less than the extra accountant time and keeps the deductions.
How long does a monthly session take without software?
Typing and categorising a month of transactions into a spreadsheet by hand is usually an hour or two, plus the GST calculations. With AI categorisation from an uploaded statement, most of that time disappears.
General information only, not tax advice. Check your own situation with a registered tax agent or the ATO.
Twenty minutes a month, and the BAS does itself
Upload each month’s bank statement and FlowFi categorises it, tracks GST and reminds you before every deadline.
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