Comparison
Those are good products, and for many firms the right answer is to buy one. This page is for the firms where it isn't, and how to tell the difference.
Karbon, Canopy, TaxDome, and CCH Axcess Workflow exist because most accounting firms run similar processes, and a well-designed shared model serves them well. If your firm is small, your engagement types are standard, and your tools are the common ones, one of those products will be live in a week and cost less in year one than any custom build.
We say this on the first call too. A custom platform that a firm did not need is a bad outcome for everyone.
The differences that decide it, without a feature checklist nobody reads.
| Subscription practice management | Custom platform | |
|---|---|---|
| Pricing model | Per user, per month, for as long as you use it. Cost rises with headcount, including seasonal and admin staff. | One fixed project price ($40K–$80K for most firms) plus an optional flat monthly plan. Unlimited users. |
| Fit to your process | You configure within the vendor's workflow model. Stages, roles, and review structure bend toward the product. | Built from a map of how your firm actually runs engagements. Your stages, your sign-off rules, your terminology. |
| Integrations | The vendor's integration list. Good coverage for common tools, nothing for your legacy or niche systems. | Whatever the firm runs, including in-house databases and older tools, priced into the scope. |
| Ownership | You rent access. Your data is exportable; the workflow, automations, and history live in their system. | You own the code, the database, and the infrastructure. Take it to any developer or host at any time. |
| Time to live | Days to weeks. Fastest way to get a baseline workflow tool in place. | 8–16 weeks from kickoff, with a working system to click through by week two. |
| Changes after launch | Feature requests go into a vendor backlog shared with thousands of firms. | Changes are yours to make, either through a support plan or any developer you choose. |
| Client-facing side | A standard client portal with the vendor's branding options. | A portal that matches your intake, document, and signature flow exactly, under your brand. |
| Risk | Price changes, feature removals, and acquisitions are outside your control. | You depend on the builder during the project; after handover the asset is yours regardless. |
Two of the three usually means the math favours a custom build within two to three years, before counting the hours the workarounds cost. The process cost calculator puts numbers on that.
No. If your firm is under about ten people, runs a fairly standard tax and bookkeeping practice, and has no unusual integrations, a subscription is the right call. It is faster, cheaper in year one, and good enough. Custom pays off when the process is specific, the headcount makes per-seat pricing expensive, or the firm wants to own the asset.
Staying inside one vendor's suite has real advantages in data flow. The question is whether the workflow module matches how your firm reviews and signs off work. Firms that have bent their process to fit the module, or run engagement types it handles poorly, are the ones who talk to us.
Three questions. Have you built spreadsheets or manual steps around your current tool to make it fit? Are you paying seats for people who barely use it? Is there a system the tool cannot talk to that matters? Two yeses usually means custom is worth pricing out.
Yes, and many firms do. The subscription years teach you what your process actually needs. Client lists, engagement history, and documents export cleanly, and migration is part of the fixed scope.
What the custom side looks like in practice: audit workflow software and tax workflow software.
Twenty minutes on how engagements move through your firm today. If the answer is "buy Karbon", we will say so.
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