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Should you have a business app built, or subscribe to off-the-shelf software? The question often comes after months of shared spreadsheets and lost messages, when the team feels it works for the tool rather than the other way round. There is no universal right answer, but there are signs that tip the balance one way, and a third path that is often forgotten: keep the off-the-shelf tool and add what it lacks.
In short
Off-the-shelf software wins as long as your way of working fits its boxes: it costs less and starts right away.
Custom is justified when your teams work around the tool every day, or when your way of working is your advantage.
Compare over three years, counting the time lost to workarounds, not just the subscription against the quote.
Before replacing software, check whether a small app that plugs into it would be enough.
What you are really buying in each case
The two options do not buy the same thing, and that is where the comparison most often goes wrong.
Off-the-shelf software
A subscription, often per user, that grows with the team
Updates made by the vendor, on its own roadmap
A way of working already designed, which you have to adopt
Your data at the vendor, with the export it provides
A custom app
An upfront investment, then a monthly running cost
Changes decided by you, which you fund
A tool that follows your way of working
Code and a database in your name
The running cost of a custom app is not zero, but it is often modest at the start. For example, the Pro plan of Supabase, a common back end for this kind of app, starts at US$25 a month with daily backups, according to its pricing page. These lines are detailed in our article on what drives the price of an app.
The signs that point to off-the-shelf software
Off-the-shelf software is often the right choice, and there is no shame in saying so. It wins when:
- The process is standard. Accounting, payroll, invoicing: vendors have put years of rules and edge cases into them, and keep up when the law changes.
- The team is ready to adopt the tool’s method. If the software’s way of working is as good as yours, adopting it costs less than rebuilding it.
- You need to start next week. A subscription opens in a day; an app, even a fast one, needs scoping.
- Nobody will own the tool internally. A custom app needs someone who decides how it evolves.
The signs that point to custom
Conversely, some signs do not lie:
- Your teams work around the tool every day. A spreadsheet next to the software, photos sent by messaging app, information re-keyed in the evening: each workaround is a cost the subscription does not show.
- Your way of working is your advantage. If clients choose you for the way you follow their file, bending it to a generic tool weakens it.
- Some rules must be right, without exception. A counter, a date, an access right: when a mistake is expensive, the rule must be enforced by the server, not by everyone’s goodwill.
- The per-user price rises faster than usage. As the team grows, the subscription follows, even for people who look at two screens a week. The full calculation is in our article on the three-year cost of subscription software.
From the field
In Challenge Us, the server sets the day of every entry
Challenge Us, a group-challenge app we built, computes the day of each entry in the participant’s time zone, on the server: the phone clock cannot be used to cheat. This kind of rule, specific to one use, is what justifies a tool built around it.
The middle path: extend the tool rather than replace it
Between “buy everything” and “build everything” there is an often cheaper option: keep the software that does the essentials well, and add a small app for the missing feature.
Palmora Property, a real-estate agency in Phuket that we work with, runs its listings from the Twenty CRM, self-hosted, which serves as its back office. The team lacked one feature: sorting a listing’s photos and changing its status without leaving the CRM. Rather than replace the tool, we added a small custom app to it, described in the Palmora case study. The CRM keeps doing what it does well; the app only does what was missing.
This path requires open software: a documented API, the ability to add objects or apps. It is a criterion to check before choosing a tool, and we cover it in our article on using Twenty beyond the CRM. Sometimes a simple automation between two pieces of software is enough, with no screen at all: see when a rule is enough, without AI.
How to compare the two over three years
- Write what the tool must do on day one.
Not the wish list: what serves at launch, and what will wait.
- Price the subscription over three years.
With the number of users expected at the end, not today’s, and the paid options you will need.
- Price the custom app over three years.
Development, monthly running costs and maintenance: an app’s budget after launch can be planned from the quote.
- Measure the workarounds.
The hours spent each week re-keying, searching, chasing: the hidden cost of an ill-fitting tool.
- Check the exit door.
In both cases, can you get your data back in a readable format if you change your mind?
What custom does not fix
An app does not clarify a fuzzy process: it freezes it. If nobody can say who approves what, the app will encode the hesitation. Better to write the journey first, then test it with the people who will use it, for example with a clickable prototype, before the first line of code.
Nor does it replace adoption. An app the team did not ask for ends up next to the spreadsheet it was meant to replace. The people who will use it must be in the loop from scoping.
If custom wins, our app development starts with written scoping of what the app does on day one, then puts a version in the hands of your first users before thinking about the stores.
Frequently asked questions
Is a custom app always more expensive than off-the-shelf software?
At the start, almost always. Over three years, not necessarily: it depends on the number of billed users, the paid options and the time lost to workarounds. Compare both over the same period, with the running costs and maintenance of the custom app, and the subscription priced at the number of users you will have at the end, not today.
Can we start with off-the-shelf software and move to custom later?
Yes, and it is often wise: off-the-shelf software teaches you what you really need. The condition is being able to get your data out in a readable format. Check the export before signing, and keep track of the workarounds the team invents: they are what will write the app’s specification.
What is an app that extends existing software?
It is a small app that plugs into software you keep, through its API, to add the missing feature: an entry screen for the field, photo sorting, a tracking board. The software remains the source of the data; the app only does what the software cannot. It requires open, documented software.
Who owns a custom-built app?
You should own it entirely: the code, the database, the store accounts and the hosting access should all be in your name, and the contract should say so before signing. Without that, changing provider or taking the app in-house may mean rebuilding part of what you paid for.
Sources
- Supabase pricing page (new tab)supabase.com
Jim · founder of Brain Plus AI
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