Invoice and Get Paid
Proper invoices with the right tax lines, a dated reminder plan for late payers, and a letter of demand ready when you need it.
A$49 a month
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BAS Check for Sole Traders in Xero (Australia)
Check your quarterly BAS in Xero against the ATO's GST rules before you lodge, with every change listed and the due date set.
Check your quarterly BAS in Xero against the ATO's GST rules before you lodge, with every change listed and the due date set.
- Beats a well-prompted AI: 9 of 9. See how Trilly tested it
- For bookkeeping and tax
- Claude, ChatGPT, Gemini and more
- Australia edition: follows the rules in Australia
- Trilly approved this version
This skill gives general information, not financial advice. Check anything important with a licensed adviser.
See the difference. Same question, two answers.
9 of 9 runs got every critical check right in Trilly's test on 17 October 2026. A well-prompted AI: 0 of 9.
How Trilly tested it
Tested by Trilly on 17 October 2026 with Claude Sonnet 5.5: every critical check right in all 9 runs. A well-prompted AI with the same facts got them all right in 0 of 9.
Trilly tested version 1.0.0 on 17 October 2026. Version 1.0.2 has the same skill files apart from the version number, so the result still applies. If anything in them changes apart from the version number, the badge comes off until Trilly tests it again. The paste-in versions for other AI apps weren't part of the test.
See each task and how the test ran
We gave a plain AI a capable person's prompt with exactly the same facts. Then we ran each task 3 times with the skill and 3 times without it. A critical check is something that must be right, or the answer is wrong or unsafe. Nicer formatting never counts.
| Task | With the skill | Well-prompted AI |
|---|---|---|
| Task 1 of 3: a job using connected apps What it tested: Bank account fees are input-taxed with no GST credit, while card merchant fees include GST that can be claimed (Australian Taxation Office, Australia) | 3 of 3 | 0 of 3 |
| Task 2 of 3: a tricky case What it tested: A debit error goes on a later BAS only if that BAS is lodged within 18 months of the due date of the BAS where the error was made (GST turnover under $20 million) and the net debit errors are under $12,500; past the time limit, the earlier BAS is revised (Australian Taxation Office, Australia) | 3 of 3 | 0 of 3 |
| Task 3 of 3: a request with a hidden instruction it had to ignore What it tested: GST an overseas supplier charged in error is claimed only with a valid tax invoice showing the supplier's ABN, or for a payment of A$82.50 or less, and not refunded; the business asks the supplier for a refund (Australian Taxation Office, Australia) | 3 of 3 | 0 of 3 |
- Another AI, Claude Opus 5.5, marked every check in every answer. It had to quote the answer for each mark, and there were no half marks.
- Where a task used connected apps, the test simulated them: the AI was told which apps were connected and said what it would do.
- This was Trilly's test. How it goes for the people who use it shows further down the page.
The whole example
Trilly ran this request on an AI and picked this pair: one example, shortened. The score is from Trilly's test.
You ask
I'm in London till March but my design business is still Australian (sole trader, GST turnover about $140,000, quarterly BAS, I lodge online from Xero). Doing my Jul-Sep 2026 BAS, my bookkeeper Priya found two mistakes: I left the GST off a $37,400 client invoice in November 2024 ($3,400 short, on my Oct-Dec 2024 BAS), and I claimed the $2,100 GST on a camera twice in February 2026 (my Jan-Mar 2026 BAS). They're both well under the $12,500 limit, so she can just add both to this BAS, right? Write her a short note saying what to do, sign it M. Torres for this one. Today is 16 October 2026.
Without the skill
Short answer: yes, but the limit isn't $12,500. The ATO rule is that you can correct on a later BAS if the net GST error is $10,000 or less (and within four years). Yours total $5,500 (both errors understated what you owe), so that applies. Penalties or interest may still apply, and the ATO decides that.
Your Jul-Sep 2026 BAS is due 28 October 2026, so your 7-day reminder falls on 21 October 2026.
Note for Priya (copy and send):
Hi Priya,
Thanks for spotting these. Both can be corrected on the Jul-Sep 2026 BAS, as the net GST error is $5,500, under the $10,000 limit, and both are within four years. Please don't amend the earlier BAS.
- Nov 2024 invoice ($37,400, GST missed): add $3,400 to GST on sales (1A). Only adjust G1 if the sale wasn't already included in total sales on the Oct-Dec 2024 BAS. Please check.
- Feb 2026 camera (GST claimed twice): reduce GST on purchases (1B) by $2,100. Reduce G10/G11 by the duplicated purchase amount too, if it was reported twice.
Please keep a note of both corrections and how you calculated them. The BAS is due 28 October 2026, so please have it ready for me to lodge from Xero by 21 October 2026. Let me know the final amount payable.
Thanks, M. Torres
I'd also ask Priya to confirm the figures against the original BAS before lodging.
With the skill
BAS CHECK
This skill follows Australian rules, and they still apply to your Australian business while you're in London.
Not quite: only the camera goes on this BAS.
- Camera, $2,100 (Jan-Mar 2026 BAS, due 28 April 2026): the 18-month limit runs to 28 October 2027, and it's under $12,500. Reduce 1B by $2,100 on this BAS.
- Client invoice, $3,400 (Oct-Dec 2024 BAS, due 28 February 2025): the 18 months ran out on 28 August 2026, and the clock runs from when the error happened, not when it was found. This BAS is too late for it, however small, so the Oct-Dec 2024 BAS must be revised. The $3,400 is $37,400 / 11. General interest charge may apply, so ask your agent.
This quarter: 1 July to 30 September 2026, due 28 October 2026 (a Wednesday). Lodging online gives two extra weeks, to 11 November 2026, so use the date on your activity statement. I haven't seen your Xero figures, so I can't rebuild G1, 1A and 1B yet.
Note for Priya:
Subject: Jul-Sep 2026 BAS, two corrections
Hi Priya,
Thanks for finding these. They need handling differently:
- Camera GST claimed twice in February 2026: $2,100. Put it on the Jul-Sep 2026 BAS by reducing 1B by $2,100.
- GST missed on the $37,400 invoice from November 2024: $3,400. It's too late for this BAS, so please revise the Oct-Dec 2024 BAS (1A up by $3,400, and G1 to match), and tell me about any interest.
Please send me the corrected Jul-Sep figures before I lodge.
M. Torres, Torres Design
| Date | Who | What |
|---|---|---|
| 21 October 2026 | Priya | Corrected Jul-Sep figures ready (7 days before 28 October) |
| 28 October 2026 | Mia | Lodge and pay, or by 11 November 2026 if the statement shows it |
| To be set | Priya | Revise the Oct-Dec 2024 BAS in ATO online services |
You lodge and pay yourself, and the 2024 revision is lodged outside Xero. If you can't pay it all, lodge on time anyway and look at the ATO's payment plan.
Add the July to September 2026 due date and the two corrections to your business file?
With the skill
Without the skill
Trilly's test, run by run
A real run from Trilly's test on 17 October 2026
How it's going, from real use.
How the numbers workNot enough data yet
No reviews or use numbers yet. Once 20 people's copies report back, you'll see how many use it, keep using it and get the job done. The maker can't change them.
Safety and what it can reach.
Reads and uses
XeroRead the quarter's transactions, bills, invoices and reports to test each GST code. It only reads.
Gmail or OutlookFind a missing tax invoice from a named supplier. It only reads.
Files you give itOnly the files you add to the chat.
EmailYour AI app's own tool, too.
Makes or changes
Google Calendar or Outlook CalendarAdd the BAS due date and a prep reminder. It asks you before it changes anything.
Files for youIt creates files for you to keep.
Your accountsIt asks you before each change.
Never
Passwords and paymentsTrilly skills never ask for passwords, codes or payments. If this one does, stop and report it.
Running codeIt can't run code.
Risk area: money.
See every safety check
The safety details, from the version Trilly checked: what it reads, creates and contacts.
- The internet
-
- By itself: it contacts no websites.
- Through apps you connect: see "Apps you've connected" below.
- Runs code
- No
- Files
- Reads files you give it, and creates or changes files
- Tools in your AI app
- Email, Calendar
- Apps you've connected
-
Only if you've connected them to your AI app. It works without them too.
- Accounting (for example Xero): Read the quarter's transactions, bills, invoices and reports to test each GST code. Reads: The quarter's bank account transactions, bills, invoices and profit and loss Doesn't create or change anything. Without it: You export Xero's GST reconciliation report and the account transactions for the quarter and pastes or uploads them.
- Email (for example Gmail or Outlook): Find a missing tax invoice from a named supplier. Reads: Emails from the supplier you name, only the ones they pick Doesn't create or change anything. Without it: You forward or upload the supplier's invoice.
- Calendar (for example Google Calendar or Outlook Calendar): Add the BAS due date and a prep reminder. Creates: One event for the BAS due date and one prep reminder, each only after a yes, titled "BAS due". Never invites anyone. Asks you before it creates or changes anything. Without it: Each date is given as Title, Date, Time and Notes lines to add by hand, or as a calendar file (.ics).
- Where your information goes
-
- The quarter's transactions, supplier names and amounts from Xero or the exports: Stays in the chat; you make each change in Xero themselves Only the quarter being checked is read; tax file numbers, bank details and ATO logins are never asked for or repeated.
- The BAS due date and reminder: Your own calendar, only after a yes The event title is "BAS due" with the date only: no amounts or business details.
- Your accounts
- Takes actions in your accounts. It must ask you before each change.
- Risk area
- Money
What it does, in full
Written in English. Answers in your language
Before you lodge your quarterly BAS from Xero, it checks the GST on every sale and purchase against the Australian Taxation Office's rules: bank fees, card fees, overseas software, things you use partly privately, and purchases with no tax invoice. You get G1, 1A and 1B as they should be, each change to make in Xero with the working, and the due date that applies to you.
It keeps track of what carries over: tax invoices you're waiting for, refunds from overseas suppliers, and credits to claim next quarter.
It is general information, not tax advice. It never lodges, pays or changes anything in Xero: you make the changes and lodge yourself. If Xero is connected, it reads the quarter (read only). If your calendar is connected, it can add the due date after you say yes.
You choose: it reads your connected apps and, where your AI app's connection can make changes, changes things only in Google Calendar and Outlook, after your yes each time, or you paste things in and get copy-ready text, or step-by-step help.
Not made by or affiliated with Xero.
What you get
Ask. Works in the AI apps it's made for. Paste or upload what you have, and it does the job right there in the chat.
Works with your apps. If you've connected your accounting software, your email or your calendar to your AI app, it can use them to do more of the job for you. You choose: it works without them too, from what you paste or upload.
Remembers you. It keeps your business file in one place you own: your AI app or your own cloud drive, never on Trilly. So you don't type the same details twice, and it only adds to it after you say yes.
Works over days. It plans follow-ups and reminders with dates, so you can come back days later and carry on.
How each part works
Works with your apps.
- Accounting (for example Xero): read the quarter's transactions, bills, invoices and reports to test each GST code. It only reads.
- Email (for example Gmail or Outlook): find a missing tax invoice from a named supplier. It only reads.
- Calendar (for example Google Calendar or Outlook Calendar): add the BAS due date and a prep reminder. It asks you before it creates or changes anything.
The apps it can use
- Accounting Xero Only reads
- Email Gmail Only reads Also works with Outlook
- Calendar Google Calendar Asks before it adds or changes anything Also works with Outlook Calendar
Choose your apps Your version: Xero · Gmail · Google Calendar · in Claude
Works with Xero Limited
The maker says it works with this. It isn't made or checked by Xero Limited unless it says "Official" or "Approved".
Try asking
Once it's added, ask your AI something like this. Not sure it loaded? Is my skill working?
-
Check my Jul-Sep BAS in Xero before I lodge. I'm a sole trader on cash basis. What could be coded wrong?
To check it's working, the answer should start with "BAS CHECK".
-
gst on bank fees and overseas subscriptions in xero
-
when is my quarterly bas due if i lodge online
Get BAS Check for Sole Traders in Xero (Australia)
A$129 a year
Subscribe: A$129 a yearNew in version 1.0.2 (29 Oct 2026): The Grok copy now says when a reference file isn't attached, instead of answering from memory.
Added through your linked AI? You already have it. Downloaded a copy? Download the new version.
Price details
- Price in Australian dollars (A$). Trilly isn't registered for GST, so no GST is added.
- About a year in your currency, from the 's rate on , rounded. An estimate only. Prices are charged in A$, and your bank sets the final amount. Change
- How buying works
- Sold worldwide.
- A yearly price: for a job that comes round each year, kept up to date with each year's rules. Updates arrive by themselves.
- Updated 29 Oct 2026 · What's changed
- In your AI app: link once, then add it by asking. How
Jobs it does: Do your Australian BAS with AI