A quote is a contract the moment it is accepted. Pick the software on what happens next.
Quoting software for a trade is decided by three things that happen after the quote is sent: whether a variation can be issued and accepted in writing, whether a deposit is taken inside the legal cap at acceptance, and whether the acceptance itself would stand up. Six products publish enough to compare. We have built against two of them.
Read this first: two of six implemented, and the rules matter more than the brand
We have built against ServiceM8 and Simpro in production, and against Xero and Stripe, which sit under most of these. Tradify, Fergus and AroFlo are described from their own pages, read on 3 September 2026, and nothing more. Where a claim below comes from experience it says so; where it comes from a marketing page an hour ago, it says that too.
The reason this page leads with the law is that the law is what a quoting workflow has to satisfy, and it is the part that stays true after every vendor reprices. A quote given to a specific customer with clear terms, scope and price can be an offer, and acceptance can be written, by conduct such as paying a deposit, or by clicking accept in a quoting platform (Sprintlaw, 20 June 2025).
This is not legal advice. It is the published rules, linked, and the published product facts, linked, put next to each other — which almost nobody does.
Variations: in writing, before the work, or you may not get paid
For QBCC-regulated domestic building work in Queensland you must present a variation to the home owner in writing and the home owner must agree in writing. The document must describe the variation, state the date of the request, state the change to the price or how it will be calculated, and be given before the variation work starts or within 5 business days of agreement, whichever is first. You cannot require payment for a variation before its work starts (QBCC, contract changes and variations, read 3 September 2026).
Software either models that or it does not. Simpro publishes variation handling as a first-class object — standard variations and linked variation quotes attached to the original job. ServiceM8 handles a variation as a further quote or an edited invoice, which works but leaves the paper trail to you. Tradify, Fergus and AroFlo do not name variations on their pricing pages; ask on the demo and ask to see one issued and accepted from a phone.
Plumbers say variation. Not change order, not add-on. If a vendor cannot say the word, be wary of what the software calls it.
Deposits: the cap, and who takes the money
The QBCC deposit caps are 20% for work at $3,300 or less, 10% for $3,301 to $19,999 and 5% for $20,000 and over, with 20% permitted only where customised off-site work is more than half the contract (QBCC, deposits and progress payments). Other states have their own caps; check yours.
ServiceM8 takes the deposit at the moment of online acceptance — you set a percentage or a fixed amount as a default, per client or per job, and the customer is prompted to pay it to proceed — but only if ServiceM8 Pay is switched on (ServiceM8 help). That is the right design and a real lock-in: deposits and the payment processor come as a pair.
Card fees are the hidden line. Stripe charges 1.7% plus $0.30 including GST on domestic cards with lower pricing flagged from 1 October 2026 (Stripe Australia); ServiceM8 Pay runs from 2.10% on the free plan to 1.49% on Premium, plus 30 cents (ServiceM8 pricing). On a $1,500 deposit the difference between the best and worst of those is about nine dollars. Not nothing on 200 jobs a year.
E-signature: what makes an acceptance stand up
Under section 10 of the Electronic Transactions Act 1999 an electronic signature is effective where a method is used to identify the person and indicate their intention, the method is as reliable as appropriate for the purpose or proven in fact to have worked, and the recipient consents (Electronic Transactions Act 1999, s 10). A typed name in a portal, with the time, the document version and the email it was sent to recorded, generally meets that. A reply saying "yep" generally meets it too, but is harder to find in eighteen months.
Simpro’s online quote acceptance portal lets the customer sign by typing their name, updates the quote status automatically and can attach a signed PDF to the quote (Simpro, 17 December 2019). Xero’s online quotes let a customer accept, decline or comment with one click and convert to an invoice, without a signature (Xero, send quotes). Tradify publishes "Quote Options & Online Acceptance". The bar is the record, not the squiggle.
Six products, on what they publish
Australian pricing as published on 3 September 2026, GST as stated. "Implemented" means in production; "documented, not implemented" means read carefully and never run.
- #1ServiceM8 — deposits at acceptance done right, tied to its own payments$0 for 30 jobs, then $29, $79, $149 and $349 a month including GST by jobs per month, unlimited users; SMS 10 cents; ServiceM8 Pay 2.10% to 1.49% plus 30 cents (pricing). Online acceptance with deposit prompt; variations by further quote. Full public API. Implemented — integration page. The constraint: deposits require ServiceM8 Pay, and job-count metering punishes high-volume low-value quoting.
- #2Simpro — the only one with variations as a first-class object, and no published priceNo prices anywhere on its Australian pricing page, "Request Pricing" only (Simpro pricing). Standard and linked variation quotes; typed-name e-signature via the acceptance portal with signed PDF attached; full API with signed webhooks. Implemented — integration page. The constraint: it is a project-scale system, and you will not know the price until a sales call.
- #3Tradify — AUD per user, online acceptance with options, progress invoicing$48, $52 and $62 AUD per user per month excluding GST for Lite, Pro and Plus; Custom by request; 14-day trial; "Quote Options & Online Acceptance"; "Progress Invoicing — deposits, progress payments, retentions" (Tradify pricing). Documented, not implemented. The constraint: no public API, so the quote data stays inside Tradify — see ServiceM8 vs Tradify.
- #4Fergus — the cheapest AUD headline, priced per business with cheap timesheet seatsFrom $53 a month Essentials and $77 Professional in AUD, timesheet users from $26, contractor users $4 a day; Enterprise for ten-plus staff by quote; 14-day trial, no card, first charge after the end of the first calendar month; GST-compliant invoices syncing to Xero or MYOB (Fergus pricing). Documented, not implemented. The constraint: acceptance, deposits, variations and API are not on the pricing page at all — ask.
- #5AroFlo — Melbourne-built, enterprise-leaning, priced on requestNo prices published; "Request Pricing" and a 1300 number (AroFlo pricing). Melbourne. Documented, not implemented. The constraint: like Simpro, you shortlist it on a sales call, not on a page.
- #6Xero — the quoting most trades already own and do not useGrow plan $78 a month including GST after a three-month introductory rate, with quotes and invoices included (Xero pricing). One-click accept, decline or comment; convert to invoice in one click; no signature and no deposit at acceptance. Implemented — integration page. The constraint: no variations, no options, no job — but for a sole trader quoting twenty jobs a month it is already paid for.
What we would build, and what we would tell you not to
Most quoting problems are not software problems. They are a price file nobody has tidied since 2023 and a habit of quoting from the ute at 7pm. Fix those first; they are free.
When it is a software problem, it is usually the joins: the accepted quote that has to be re-typed into Xero, the deposit that sits in Stripe unmatched, the follow-up that never goes out because nobody owns it. Quote to invoice is the shape of that work, and it is deliberately the cheapest thing we sell.
What we would tell you not to do is build a quoting engine. Every product above has had its edge cases found by thousands of trades. Yours has not. The build-versus-buy framework is the longer version of that sentence.
The questions people actually ask.
01Which one should a plumber pick?
It depends on job count and variation load, which is why there is no ranking. Under 150 jobs a month with few variations, ServiceM8 at $79 with deposits at acceptance is hard to beat and we have built against it. Project work with regular variations points at Simpro, at a price you will learn on a call. A sole trader with twenty quotes a month may already own the answer in Xero. If you want the twenty-minute version for your actual numbers, that is a Leak Check.
02Is a typed name really a signature?
Under section 10 of the Electronic Transactions Act it can be, provided the method identifies the person and indicates intention, is reliable enough for the purpose, and the recipient consents. What makes it hold is the record around it — the version sent, the address it went to, the timestamp. That is what the portals give you and an SMS "yes" does not. We are not lawyers; if a contract is large, ask one.
03Why is Simpro on a list with no price?
Because it is the only product here that treats a variation as its own object, and because we have implemented against it and can say that from experience rather than from a brochure. The missing price is a real finding about how Simpro sells, and it is marked as such rather than hidden.
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