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The 28 July BAS Deadline: A Calm Person's Guide to the June Quarter

The June quarter BAS is due on 28 July if you lodge it yourself, with extended deadlines available if you lodge through a registered BAS or tax agent.

By Nick Lucock·12 July 2026·5 min read

The short answer

The June-quarter BAS is due on the standard ATO date if you lodge yourself, with an extension available through a registered BAS or tax agent. A quarterly BAS rolls up GST, PAYG withholding and PAYG instalments into one form — money that was largely never yours to keep. Reconcile your bank first, sanity-check GST against sales, then lodge. Check the ATO for your current due date, as it varies by lodgement method.

The June-quarter BAS is the one worth doing carefully. It closes out your GST year, it lands amid the other end-of-financial-year jobs, and any errors in it will surface later when your accountant reconciles the annual accounts. If you lodge yourself, the due date is the standard late-July one the ATO publishes; lodge through a registered BAS or tax agent and you generally get longer. Confirm your exact date with the ATO or your agent, since it shifts with lodgement method and with weekends.

What a quarterly BAS actually contains

One form, usually several obligations rolled together:

  • GST: the GST you collected on sales, minus the credits on your business purchases.
  • PAYG withholding: the tax you withheld from employee wages, unless you already report and pay it monthly.
  • PAYG instalments: prepayments toward your own income tax, if the ATO has placed you in the instalment system.

Owners sometimes take fright at the size of "the BAS bill" without separating those parts. The GST was never your money; the withholding was never your money; the instalment is your own future tax bill arriving early. Seeing the split changes both how the number feels and how you provision for it.

Reconcile before you touch the form

The BAS is a report on your books, so the books come first. If the quarter's bank accounts aren't fully reconciled, stop and finish that; a BAS built on unreconciled accounts is built on sand. Then run two sanity checks. Compare GST collected against your taxable sales: at the current GST rate the relationship between the two is fixed, so your software can tell you whether they line up, and a large mismatch usually means something is mis-coded, often a GST-free sale, an export, or an asset disposal sitting in the wrong place. Then scan the GST credits report line by line, and give every large or unusual transaction a few seconds of attention on its tax code.

The usual mis-codings

The same handful of errors appears in small-business files again and again:

  • Bank fees and interest claimed as if they carried GST; most are input-taxed and carry no credit.
  • Insurance claimed as fully creditable when part of the premium is stamp duty, which carries no GST.
  • Overseas software subscriptions claimed with GST that many of them don't actually charge.
  • Wages or superannuation accidentally coded to a GST-bearing account.
  • Vehicle and home-office costs claimed in full when only the business-use portion is claimable.

None of these is exotic, and all of them are found in minutes once you know to look. Fixing them before lodgement beats amending after it.

If the bill is bigger than the bank balance

Lodge anyway, and on time. Lodgement and payment are separate obligations, and the ATO treats a business that lodges honestly and then arranges payment very differently from one that disappears. Payment plans exist and are routinely arranged; silence is what escalates matters. If cash is going to be short, tell your agent early, because options narrow as the deadline passes.

Making next quarter calmer

The deadline-week scramble is a provisioning problem wearing a paperwork costume. The durable fix is to move GST and withholding out of your operating cash as you go, most simply into a separate tax sub-account each week or with each pay run, so lodgement day becomes a transfer rather than a crisis. Pair that with weekly bank reconciliation as a standing habit and the June quarter stops being special; it's just the quarter with a few extra year-end tasks attached. It's a small instance of a larger pattern we write about across the finance side of the back office: most compliance stress is really process debt, and process debt is repayable.

About the author

Nick Lucock

Chief Executive Officer, Valont

Nick leads Valont's day-to-day operations across Finance, People, Operations and Growth. He writes about how the work actually gets done — the processes, systems, and tools that keep Australian SMEs compliant and growing.

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