QuickBooks and Acomba Integration for SMBs

A quote accepted in your CRM. An invoice to create in QuickBooks. The same information — client name, address, line items, taxes — retyped by hand by someone, once a day or once a week. And a QST error or a mistyped client number that only shows up at reconciliation. Connecting your accounting software to your other tools eliminates that double entry. With QuickBooks Online, it's usually straightforward: it offers a modern cloud API and many ready-made connectors. With Acomba, installed on a Windows machine, it's doable too, but it goes through its local software development kit or a specialised connector — and it has to be planned from the start.

This guide explains how an accounting integration works, the three ways to build one, what differs between QuickBooks and Acomba, and the traps that turn a "small sync" into a headache.

Why integrate your accounting software

The cost of double entry never appears on an invoice. It shows up in your office administrator's hours, in invoices sent late because "the person who does that is on vacation", and in errors fixed at month-end.

The most common cases in a Québec SMB:

• Accepted quote → invoice: the client approves, and the invoice is created in accounting with the right lines and the right taxes.
• Timesheets → billing: approved hours become invoice lines, at the right rate.
• Online store → sales: every Shopify or WooCommerce order is recorded, with its taxes and fees.
• Payments → client status: an invoice paid in QuickBooks automatically updates the client's status in your CRM.
• Inventory → cost of goods sold: stock movements flow into accounting without retyping.

Three ways to connect QuickBooks or Acomba

The right answer depends less on technology than on your process. If you're syncing Shopify orders to QuickBooks Online like thousands of other stores, a connector will do the job well. If your invoice depends on a calculation specific to your trade — construction holdbacks, rates that vary by engagement, progress billing — a generic connector will end up making you fix by hand what it was supposed to automate.

QuickBooks Online: the most accessible integration

QuickBooks Online is cloud software, and that's what makes it easy to integrate. Intuit publishes a documented API: another application can create clients, invoices and payments, read their status, and be notified when something changes through change notifications (webhooks).

Access is granted by an authorisation you give yourself, from your QuickBooks account, and that you can revoke at any time. Nobody needs your password.

Two things to know before starting a project:

• Intuit governs how its API is used. There are rate limits, and in 2025 Intuit introduced a partner programme that can charge apps beyond a certain volume of reads. An SMB rarely reaches those thresholds, but a well-designed integration only reads what it needs.
• QuickBooks Desktop is a different world. The installed version doesn't integrate like the online one: integration goes through a local component and requires the computer to be on. If you're still on Desktop, it's often the right moment to ask about migrating.

Acomba: doable, as long as you plan for it

Acomba is widely used in Québec, especially by established SMBs, distributors and construction companies. It's solid software, but designed in another era: it's installed on a Windows workstation or server, and its data lives locally.

For another application to read or write in Acomba — clients, products, invoices, orders — it has to go through its software development kit (SDK), installed on the machine where Acomba runs. In practice, an Acomba integration almost always needs a small program running on your server, bridging Acomba and your online tools.

There are also specialised connectors, built by Québec companies, that expose Acomba data as a web service. They can save a lot of time. Before choosing one, check three things: compatibility with your version of Acomba (or Acomba X), who can access the data and where it travels, and what happens when the Windows machine is off or being updated.

The traps that derail a sync

Two sources of truth. If a client can be edited in both the CRM and QuickBooks, the two versions eventually drift apart. Decide, for each type of data, which system is authoritative — and the sync always flows in that direction.

Taxes. GST, QST, exempt clients, clients outside Québec: this is where improvised integrations break. Tax codes must be mapped explicitly, never guessed.

Duplicates. Without a shared identifier, "Construction Tremblay Inc." and "Construction Tremblay" become two clients. A good integration keeps the link between each system's identifiers.

Silent errors. An invoice rejected by accounting at 2 a.m. must leave a trace and alert someone. Otherwise you find out at month-end.

Law 25. Your accounting data contains personal information. Know where it travels: a connector hosted abroad is a transfer outside Québec, which requires a privacy impact assessment.

Where to start

1. List your double entries. Who retypes what, in which software, how many times a week.
2. Pick the most painful flow, not the most impressive one. Often it's quote → invoice or hours → invoice.
3. Name the source of truth for clients, products and prices.
4. Check whether a connector exists for that exact flow. If so, try it first.
5. Go custom only when the connector can't handle your rules — or when you spend more time fixing than you save.

How ATOM approaches an accounting integration

At ATOM, we build integrations between your tools and your accounting when a standard connector is no longer enough: a client portal that creates its invoices in QuickBooks Online, a job-site app that sends its hours to Acomba, a quoting tool that no longer needs retyping. We start with a single flow, the one that costs you the most hours, make it work for real, then decide together what comes next. Your data stays hosted in Canada.