Declared bias before anything else: we build custom software. That makes this page the least likely place on the internet to find a fair answer, so every figure below comes from a vendor’s own published price list, read on 21 September 2026, and every assumption we add is labelled as ours.

At a glance

  • Assume the product wins. It usually does, and the first section explains when it stops.
  • Score one process, not the whole company. The answer is rarely the same for all of them.
  • Three years of a typical 25-person UK stack, at the vendors’ own list prices, comes to about £94,000. That is close enough to a mid-sized build that the money alone will not decide it.
  • The hybrid wins most often: keep the product, build the gap.
  • One build of ours is public and priced to the penny: 63 measured lines, £98,214.72.

Why should you start by assuming off-the-shelf wins?

Because a good product is the cheapest way to get a defined process running, and most processes in most businesses are not actually unusual. Someone else has already built it, tested it against thousands of customers, and is selling it for less per month than a day of engineering.

A product also comes with things a build does not: a support line, a roadmap somebody else funds, security patching, an ecosystem of people who already know it, and the ability to stop paying. Those are real and they are undervalued in every comparison written by a supplier of custom work.

So the burden of proof sits with the build. The question is never “would custom be better”, because custom is almost always better in isolation. The question is whether it is better by enough to justify the difference, for this process, for three years.

What are the four ways a good product stops fitting?

It is rarely a sudden failure. It is four specific frictions, and you can name which one you have.

The spreadsheet appears beside it. Somebody keeps a separate sheet because the product cannot hold something the business needs. That sheet is the shape of the gap, and it is the single most reliable signal in this whole exercise.

The reporting stops answering the question. The data is in there, and getting the view a director actually wants requires an export and half a day. This is the most common reason a business says it has outgrown a system, and often the cheapest to fix without replacing anything.

The exception path escapes the software. The routine jobs run inside the product and the awkward ones run by email. Over time the awkward ones get more valuable, and the system of record stops recording the money.

Per-seat pricing outgrows the value. You are paying full price for people who only need to look at one number once a week. This is a pricing mismatch, not a functional one, and it is worth naming as such before commissioning anything.

How do you score one process rather than the whole company?

Pick one process. Not the department, not the company. A quote-to-order sequence, an onboarding, a monthly reconciliation. Score these eight, one to five, and write the reason beside each.

  1. Fit today. How much of this process does the product already handle without a workaround?
  2. Workaround cost. How many hours a month go into the spreadsheet, the re-keying and the chasing that the product caused?
  3. Exception rate. What share of cases leaves the software entirely?
  4. Reporting gap. Can a director get the view they need without an export?
  5. Seat economics. How many licences are paying full price for light use?
  6. Rate of change. How often does this process change? High scores here argue for the product, not the build.
  7. Data ownership. If you left the vendor tomorrow, what would you actually get back, including history and attachments?
  8. Distinctiveness. Is the way you do this genuinely a reason customers choose you, or is it just how it ended up?

A high total on two, three and eight argues for building. A high score on six argues loudly against it: you would be paying to set concrete around something still moving. And if the only high score is five, you have a procurement problem, not a software problem, and the cheapest fix is a conversation with your account manager.

What does three years of seats cost against one build?

Here is the sum most comparison pages skip, done properly. Every unit price is the vendor’s own published UK list price, read today and linked below. The seat counts are our assumption for a 25-person business and are stated so you can change them.

Line Published list price Assumed use 36-month cost
Salesforce Sales Cloud, Core edition £156 per user per month, billed annually 15 users £84,240
Monday.com, Basic £8 per seat per month, billed annually 25 seats £7,200
Xero Ultimate £70 per month after the introductory period 1 subscription £2,520
Three-year total £93,960

Now the other side, using published UK build bands rather than a quote from us. Make It Simple publishes small bespoke systems at £20,000 to £60,000, and Unity Bridge publishes a focused custom CRM at £20,000 to £50,000 over two to four months. Take the middle at £45,000. Add hosting at the £200 to £2,000 a month that Square Root publishes, say £400. Add maintenance at Square Root’s 15 to 25 per cent of build cost a year, say 20 per cent, which is £9,000. Three-year total: £45,000 plus £14,400 plus £27,000, or £86,400.

The honest conclusion is that those two numbers are close, and anybody who tells you the arithmetic clearly favours one route has chosen convenient assumptions. What moves it is not the headline: it is whether the build genuinely removes the licences, whether the seat count grows, and whether the process changes. Run it with your own numbers, and if the two totals land within twenty per cent of each other, stop using cost as the deciding factor and use the eight-factor score instead.

One caution about the build column: a build does not remove your accounting package or your email. Most builds replace one licence, not the stack.

The hybrid that usually wins: keep the core, build the gap

In a business of £1m to £50m turnover, the right answer is usually neither pure route. It is to keep the product as the system of record, and build the specific piece that does not fit around it.

That might be a pricing engine that reads from the CRM and writes back. A document generator that produces the thing your customers actually receive. A view for the people who only need to look, so you stop buying full seats for them. Each of those is a small, bounded build with a clear stopping point, and each leaves the product doing what it is good at.

The hybrid is proposed less often than it should be, and the reason is commercial: it is the smallest sale available to a supplier of custom software. It is also usually the best one, which is why we lead with it.

How do you test it before spending anything?

Run one week of work through the question before you commission anything. It costs nothing but attention and it settles most arguments.

Choose one representative job. Not the biggest, not the worst. A normal Tuesday.

Include one awkward exception. Pick a case from the last month that did not follow the process. The exceptions are where the real requirement lives.

Follow the data all the way through. Where does each field come from, who types it, and how many times is the same fact entered? Count the re-keying.

Price the missing work. The hours in the spreadsheet, the chasing, the corrections. Use a loaded hourly cost and state it.

Test the custom option too. Describe what would have to exist for this job to run without the workaround, in one paragraph. If you cannot write that paragraph, you are not ready to commission a build.

A real priced build you can inspect

Off-the-shelf estimating software exists and some of it is good. This is what the custom answer produced on a real job, so you can compare like with like.

QSQuoter is a system we built and run. On 14 July 2026 it produced an issued job for Cheadle Construction of Cheadle, Stockport, reference JAY-AA-20260713: a first-floor build-over extension in Heaton Moor, priced across sixty-three measured lines at £98,214.72 including VAT, published in full so every line traces back to a dimension somebody can check.

The claim is deliberately narrow. It shows that a custom system can produce a priced professional document to an auditable standard, in daily use. It does not prove that a build beats a product for your process, and we do not say it does. What we cannot show you yet is stated plainly on our evidence page.

When is custom the wrong answer, including for us?

When your objection to the product is the subscription fee. Building to avoid a licence is almost always the more expensive way to avoid it.

When the process changes every few months. Products absorb change on somebody else’s budget; builds absorb it on yours.

When nobody internally owns the process. Custom software makes a defined process faster. It does not create the definition, and a build commissioned into a vacuum becomes an expensive version of the old confusion.

When you cannot say what “working” looks like in a sentence with a number in it. If success is not measurable, neither is completion, and neither is the argument about whether the supplier finished.

And when the honest answer is that the product would fit if two people agreed on a process. That is a management decision worth having before a procurement one.

What does it cost to find out?

The 30-minute fit call is free and nothing is purchased on it. If the process warrants a proper read, the AI Constraint Audit is a fixed £2,000 over fourteen days, and it ends in four documents you own: a constraint map, an opportunity map, economic cases and a ranked next step. Those documents are portable. You can take them to another supplier and get a comparable quote, which is the test of whether an audit was real.

The audit fee is not credited against a build. That is what allows the recommendation to be “keep what you have”. The systems we build, and what we will and will not take on, are described on custom process systems.

What this does not apply to

This is written for UK businesses of roughly £1m to £50m turnover with an operations director, a contracts manager or a finance lead who owns the process in question. It assumes you already run some software and are deciding what to do about the parts that do not fit.

It does not apply to sole traders or very small teams, for whom the product is almost always the answer. It does not cover regulated core systems in financial services or healthcare, where replacement carries approval requirements outside the scope of this page. It does not cover public-sector procurement. And the three-year sum above is an illustration built on stated assumptions, not a quote for anyone.

When we are the wrong choice

If the product fits and the objection is price, we will tell you to negotiate rather than build, and that conversation is free.

If you want the whole company rebuilt at once, we are the wrong supplier. We would propose the smallest useful first version, and some buyers find that underwhelming.

If you need it working next month, a build is the wrong shape and a hybrid or a product is not a compromise, it is the correct answer.

If nobody can be named as the owner of the process, no supplier can fix that.

Sources

Read on 21 September 2026.

The short answers

Each answer is the opening of the section it links to, so nothing here is written for a crawler that a reader cannot also see.

When does off-the-shelf software beat a custom build?

Because a good product is the cheapest way to get a defined process running, and most processes in most businesses are not actually unusual. Someone else has already built it, tested it against thousands of customers, and is selling it for less per month than a day of engineering.

What are the four ways a good product stops fitting?

It is rarely a sudden failure. It is four specific frictions, and you can name which one you have.

How do you decide custom versus off-the-shelf for one process?

Pick one process. Not the department, not the company. A quote-to-order sequence, an onboarding, a monthly reconciliation. Score these eight, one to five, and write the reason beside each.

What does three years of software seats cost against one build?

Here is the sum most comparison pages skip, done properly. Every unit price is the vendor's own published UK list price, read today and linked below. The seat counts are our assumption for a 25-person business and are stated so you can change them.

How do you test the decision before spending anything?

Run one week of work through the question before you commission anything. It costs nothing but attention and it settles most arguments.

When is a custom build the wrong answer?

When your objection to the product is the subscription fee. Building to avoid a licence is almost always the more expensive way to avoid it.

What is the difference between custom, bespoke and off-the-shelf software?

Custom and bespoke mean the same thing in the UK market: software written for you, which you own. Off-the-shelf is a product you licence alongside other customers and cannot change. Suppliers sometimes use bespoke to signal a higher price bracket, but there is no technical distinction.

At how many users does a custom build get cheaper than seats?

There is no universal crossover, because seat prices vary from £8 to £440 per user per month on published UK list prices. Do the arithmetic with your own vendor's list price and your own headcount. As a rule of thumb, high per-seat prices and many light-touch users move the answer towards a build faster than headcount alone.

Can we start off-the-shelf and move to custom later?

Yes, and it is usually the right sequence. The condition is that you keep your data in a form you can export cleanly. Ask the vendor what a full export contains, including attachments and history, before you commit rather than at the point you want to leave.

What happens to our data if we switch?

Structured records usually move. What tends not to move is attachments, email threads, audit history, custom fields added over time, and anything held in a vendor-specific format. Budget the migration as a project of its own, because it is often the largest single line.

How long does a custom build take compared with buying?

Buying is days to weeks. A focused custom build is commonly published at two to four months in the UK market, and a multi-module system at four to eight. The gap matters most when the problem is urgent, which is an argument for the hybrid rather than for either extreme.

What if only one part of our process does not fit?

Then build only that part. Keep the product as the system of record and build the piece that does not fit around it. This is the most common right answer in a business of £1m to £50m turnover and the one least often proposed, because it is the smallest sale.

Is custom software more expensive to maintain?

It has a different shape of cost. A product's maintenance is included in the licence you cannot stop paying. A build has hosting and a maintenance budget, commonly published at 15 to 25 per cent of build cost a year, which you can vary. Neither is free and the difference is control, not total.

Who owns the code if we commission a build?

Ask before you sign, and get the answer in the contract. It is not universal. A supplier who retains ownership and licences it back to you has sold you a product with a bespoke price tag, which is the worst of both routes.