Why UK SMEs Are Replacing Spreadsheets with Custom Web Apps in 2026

Every growing UK business hits the same wall. The spreadsheet that ran the company at five people becomes a liability at twenty-five. Formulas break. Two people overwrite each other. Nobody is sure which copy is the latest. The founder spends Sunday evening fixing a pivot table.

This is the moment most teams quietly start looking for a custom web app: a piece of software built around how they actually work, rather than another SaaS subscription that almost fits.

The honest case for spreadsheets

Spreadsheets are the best prototyping tool ever built. They are cheap, flexible, and every member of staff has used one. For a brand new process with three users and no clear shape, a shared Google Sheet is usually the right answer.

The problem is not Excel. The problem is keeping Excel as your operating system after the process has grown up.

Seven signs you have outgrown the sheet

1. You have a "master" file that only one person is allowed to edit.
2. You email exported copies because the live file is too risky to share.
3. Reports take a half day to assemble at the end of every month.
4. You discovered a formula error that had been wrong for six months.
5. Onboarding a new starter means a two-hour walkthrough of one workbook.
6. Two teams keep slightly different versions of the same data.
7. You are paying for a SaaS tool and still doing the real work in a sheet next to it.

If three or more of those sound familiar, the spreadsheet has stopped saving you time and started costing you money.

What a custom web app actually replaces

A custom web app is not a single thing. In a typical UK SME engagement we replace some combination of the following:

• A pipeline or sales tracker that has outgrown a CRM or a sheet.
• A jobs board, scheduling system or capacity planner held together with colour-coded cells.
• A quoting, invoicing or pricing calculator that lives in a workbook.
• A client portal where customers can see status, approve work and download files.
• An internal admin tool that pulls data from Stripe, Xero, HubSpot or a website.

In every case the goal is the same. Move the logic into a typed database, give each user a clear interface, and stop people editing the underlying cells.

The real cost of staying on spreadsheets

Most teams underestimate this because the cost is hidden. A useful exercise is to add up the following over twelve months:

• Hours spent on monthly or weekly reporting that a database would generate instantly.
• Hours spent reconciling versions, fixing broken formulas and recovering deleted ranges.
• SaaS subscriptions you bought because the sheet was not enough, then kept using the sheet anyway.
• Decisions made or delayed because nobody trusted the numbers.

For a 15-person UK SME that figure is usually somewhere between £25,000 and £80,000 a year. That is before you count opportunity cost.

What a custom web app costs in 2026

Fixed-scope custom web apps from FK Digital Alliance start at £15,000 and most internal tools land between £20,000 and £45,000. A larger client portal or a full operations system runs £45,000 to £90,000.

Hosting is the surprising part. A Postgres database, a React front end and an edge-hosted API for a 50-user internal tool typically costs £50 to £200 a month, not per seat. Compare that with a SaaS platform charging £40 per user per month and the maths shifts very quickly.

The stack we use, and why it matters to you

We build on React and TypeScript on the front end, a typed API layer, and a managed Postgres database via Supabase. Hosting is on the edge so the app loads in under a second across the UK.

You should care about this for three reasons:

• You own it. Source code, schema and data are yours. No lock-in.
• It is mainstream. Any competent React developer can pick the codebase up. You are not tied to one agency.
• It scales without re-platforming. The same stack runs at ten users and ten thousand.

How a project actually runs

A typical custom web app project at FK Digital Alliance takes eight to sixteen weeks, fixed scope, with a clear quote before any code is written.

1. Discovery, one to two weeks. We sit with the team that uses the spreadsheet today, map the real process, and decide what is in scope.
2. Design and prototype, two to three weeks. You see and click the app before we build it.
3. Build, four to ten weeks. Shipped in working increments so you can use early features while we finish the rest.
4. Launch and handover. You receive the code, the database, full documentation and a 30-day warranty.

Where a CRM fits in

The single most common spreadsheet-replacement we are asked for is a custom CRM. Sales, customer success and operations teams almost always start there because it is where the pain shows up first. From the CRM we often extend into job scheduling, quoting and invoicing, which together replace three or four overlapping SaaS subscriptions.

A simple test before you commission anything

Before you ask any agency for a quote, write down the following on one side of A4:

• The three workflows that hurt the most today.
• The people who touch each one and what they actually do.
• The reports you wish you had every Monday morning.
• The systems the new tool must talk to, with rough volumes.

If you can produce that page, you are ready for a serious conversation.