Flat Pricing vs Per-Client Fees: The Hidden Cost of Practice Management Software

There's a thread on AccountingWEB titled "New Year = New Software" that turns up every January like clockwork. Different firms, same complaint: "My software bill went up again and I'm not sure what I got for it." When you dig into the replies, the pattern is always the same. Per-client pricing. Per-seat licensing. Module add-ons. A bill that grows every time the firm does.

Something's wrong when the cost of managing your clients goes up faster than the revenue those clients bring in.

How practice management pricing actually works

Most UK practice management software uses one of three pricing models, and understanding the difference will save you from a very unpleasant surprise when your firm starts growing.

Per user (per seat). You pay for each person who logs in. Senta starts at around £31/month for one user, dropping to roughly £15/user at higher tiers. Xero Practice Manager is bundled with Xero HQ at around £100-150/month for a small team, but prices climb as you add staff. Sounds manageable — until you hire a part-time bookkeeper, a trainee, and a virtual assistant. Suddenly your "affordable" software costs 40% more than it did six months ago.

Per client. Some platforms charge based on how many active clients you manage. Capium, for example, uses a tiered model based on client count. This creates a genuinely perverse incentive: your software punishes you for winning new business. Take on 20 new clients this quarter? Congratulations — your overheads just went up too.

Per module. IRIS is the classic example. Accounts production is one licence. Tax is another. Practice management is another. Document management is another. Each module has its own pricing, and each one typically charges per user on top. The total bill for a firm of eight running the full IRIS suite can easily hit £1,000/month or more — and that's before you add on any of their newer products.

The growth penalty

Here's the maths that nobody shows you on the pricing page.

Say you're a firm of five, managing 200 clients. Your practice management costs £75/month at the per-seat rate. Not bad. Then over the next two years, you grow to ten staff and 400 clients. Your revenue doubles — brilliant.

But your software bill? That's gone from £75 to £150. Or if you're on per-client pricing, it might have gone from £100 to £200. On a per-module setup like IRIS, the jump is even steeper because you're multiplying modules by users.

None of that extra cost bought you a single new feature. The software didn't get better. You just got charged more for doing what you were already doing, with more people.

On AccountingWEB's "Nomisma" thread (discussing alternatives to expensive platforms), one practitioner put it bluntly: "I'm paying more each year for the same product, just because I hired." That frustration is everywhere once you start looking for it.

What flat pricing looks like

Flat pricing means one price for your whole firm. No per-seat charges. No per-client tiers. No module add-ons. Ten users or two — same bill.

The obvious benefit is predictability. You know what you're paying this month, next month, and next year. Your costs don't spike when you bring on a new team member or win a batch of new clients. You can actually budget for software without a spreadsheet of "what ifs."

The less obvious benefit is behavioural. When there's no cost to adding a user, you actually give everyone access. The office manager gets a login. The part-timer gets a login. Even the partner who "only checks things occasionally" gets a login — because why wouldn't they?

With per-seat pricing, firms routinely share logins to avoid extra charges. That creates audit trail gaps, security issues, and the kind of "who changed this?" arguments that waste everyone's time.

The trade-offs (because there always are some)

Flat pricing isn't magic. There are legitimate reasons why vendors use per-seat or per-client models.

Infrastructure costs scale with usage. More users means more server load, more storage, more support tickets. Vendors need to cover that somehow. A flat-price product that gets hammered by a 50-person firm while charging the same as a two-person firm has a sustainability problem.

Per-seat pricing aligns cost with value. The argument goes: if ten people are using the software, it's delivering ten times the value, so it should cost more. That's not unreasonable in theory. It just doesn't feel that way when you're hiring your sixth member of staff and watching your bill tick up.

Some flat-price products make up for it elsewhere. Higher base price, usage limits on storage or API calls, mandatory onboarding fees. Check the fine print. "Flat pricing" means nothing if there are caps hiding in the terms.

The honest middle ground: flat pricing works best for small-to-mid-size firms (say 3 to 30 staff) where the team is big enough that per-seat costs sting, but small enough that the vendor's infrastructure costs stay reasonable. That's the sweet spot. And not coincidentally, that's exactly the market most UK accountancy firms sit in.

Comparing the real numbers

Let's lay it out for a firm of eight staff managing 300 clients:

• Senta (per user): roughly £15-20/user/month at that tier. Call it £130-160/month.
• Xero Practice Manager (bundled pricing): approximately £150-200/month depending on your Xero plan, but you'll likely need add-ons for document management and client portals.
• Capium (tiered): pricing varies, but the mid-tier plans for 300+ clients typically start around £100-200/month.
• IRIS Practice Management (per module + per user): varies wildly, but £300-500/month for eight users across multiple modules is common. Some firms report higher.
• Fortium (flat pricing): one price, all users, all features. No per-seat charges, no module add-ons.

The gap between "affordable at two users" and "expensive at eight users" is where per-seat pricing really bites. If you're planning to grow, model out what your software costs in three years, not just today.

What to ask before you sign

Before committing to any practice management platform, run through these:

1. What's the total cost at double my current headcount? Not the base price. The actual price when you've hired three more people.
2. What's included and what's an add-on? Document storage, client portal, email integration, e-signatures — these are essential features, not premium extras. If they're behind a paywall, factor that into the real cost.
3. What happens to my data if I leave? This matters more than pricing in the long run. If you can't export your data in a standard format, you don't own it. Check the exit terms. (We wrote more about this in our guide to moving away from IRIS.)
4. Is there a contract lock-in? Annual contracts with auto-renewal are standard. Multi-year contracts with early exit penalties are not. Know the difference.

The bottom line

Your practice management software should get cheaper per client as you grow, not more expensive. That's how economies of scale are supposed to work. If your current provider charges you more every time you hire or onboard a new client, you're subsidising their growth with yours.

Flat pricing isn't the answer for every firm. But for the 3-to-30-staff UK practices that make up the bulk of the profession, it removes a tax on growth that most firms have just accepted as normal. It doesn't have to be.