11 Signs It's Time to Replace Excel with Custom Software

It's time to replace Excel with custom software when the spreadsheet has quietly become the system your business runs on: orders, stock, scheduling or customer records. The clearest signs are version chaos, copy-pasting between files and tools, and one person who is the only one who really understands the workbook. If four or more of the 11 signs below sound familiar, it's worth looking at what the alternatives would cost.

Most of this applies to Google Sheets too. I build this kind of software for a living, so factor that in. It's also why each sign comes with an honest note on whether the spreadsheet itself can handle it, and why off-the-shelf software is sometimes the better buy.

The short answer

Here are all 11 signs, whether Excel can realistically handle each one, and the usual next step.

My rule of thumb: if you recognize one to three signs, clean up the spreadsheet first. If you recognize four or more, or even one of signs 3, 7 and 8, start looking at proper software. Those three are about risk rather than convenience: what happens when a key person leaves, when an error can't be traced, or when personal data ends up in the wrong inbox.

If you're already leaning towards a build, my guide to building your own platform or web app walks through the whole process from idea to launch.

Everyday signs: files, copy-paste and key people

1. Nobody knows which file is the latest

The file is called Pricing_2026_FINAL_v3_fixed.xlsx, and there's a different version in an email thread from last week. When two people work from separate copies, it's luck who has the right numbers, and time disappears into working out which file counts.

You can fix most of this inside Excel. Put one file in OneDrive or SharePoint (or one Google Sheet), stop emailing attachments, and agree that the shared file is the only one that counts. If copies keep appearing anyway, it's usually because people need their own view of the data. That's exactly what software with a shared database gives them.

2. You copy the same data between tools

An order comes in from your Shopify store or by email, gets typed into the spreadsheet, and then typed again into Xero or QuickBooks. Every manual copy is a chance for errors: swapped digits, a forgotten row, the same customer saved twice under different spellings.

Power Query and lookup formulas can remove some of the copying between sheets. Once data has to move between separate systems, though, what you need is an integration. Software can pull the order in automatically and push the invoice data on to your accounting tool, so nobody types the same thing twice.

3. One person owns the spreadsheet

There's usually one person who built the workbook, wrote the macros and knows why column Q must stay empty. When they're on holiday, everyone waits. When they leave, you're left with a business-critical tool nobody dares to touch.

This is the sign I take most seriously, because it's about risk. Start by asking that person to document what the spreadsheet does and why. It helps whatever you decide next, and it's the best possible starting brief if the spreadsheet is later turned into software.

4. People overwrite each other's changes

The file is locked because a colleague has it open, or two people edited the same cell and one change vanished. Excel in Microsoft 365 does support co-authoring when the file lives in OneDrive or SharePoint. It needs a modern file format, though, and it doesn't change the fact that everyone can still edit everything.

Software solves both problems. Each user sees and edits only what they're supposed to, and changes are saved per order, customer or task rather than in one big file everybody shares.

Signs in the numbers: errors, speed and audit trails

5. You don't fully trust the numbers

A formula pointing at the wrong range, a number typed over a formula, or a SUM that never picked up the new row. These errors are small and hard to spot, so someone ends up checking the figures by hand before every meeting.

Data validation, locked cells and Excel tables take the edge off. But as long as anyone can type anything into any cell, there's no guarantee. In custom software the rules are part of the program: an order can't be saved without a customer, a quantity can't be negative, and a price comes from the price list rather than someone's memory.

6. The file is slow and fragile

The workbook takes 30 seconds to open, recalculates on every change and crashes now and then. According to Microsoft's Excel specifications, a worksheet can hold just over a million rows, but files full of lookups and macros become sluggish long before that.

Limits can also bite harder than expected. In 2020, nearly 16,000 positive COVID-19 cases were left out of England's official figures because Public Health England imported lab results into the old .xls format, which stops at 65,536 rows, as The Register reported at the time. It's an extreme case, but the same thing happens on a smaller scale: a spreadsheet rarely shouts when it runs out of room.

Slowness is rarely something you can fix inside Excel for long. Data at that volume belongs in a database.

7. Nobody can see who changed what

A product price changed, or a customer's discount disappeared, and nobody knows when or why. Excel has version history, and Microsoft 365 can show recent changes. It isn't built to document your business over several years, though, such as who approved a particular discount last March.

If you need to show an auditor, a customer or a certification body who did what, you need an audit log. In custom software it's a standard feature: every change is stored with the user, the time and the previous value.

8. Sensitive data sits in a file anyone can open

Customer lists, employee details or health information in a spreadsheet that gets emailed around or lives in a shared folder. Access is all or nothing: either you can open the file and see everything, or you can't.

If you handle personal data of people in the EU, GDPR requires appropriate security, and that's hard to demonstrate when a file can be copied and forwarded without a trace. Software can show a salesperson a customer's contact details without exposing payroll data, and it can log who opened what. This isn't legal advice, so check with an advisor if you're unsure about your obligations.

Signs your business has outgrown spreadsheets

9. People outside the office need the data

Customers call to ask about their order status, a partner needs a list every Friday, or your field staff need the day's jobs on their phones. Someone on your team becomes a human API (a go-between who fetches and sends data): they pull an extract from the spreadsheet, save it as a PDF and send it on.

Spreadsheets aren't built to give outsiders access to just their slice of the data. A customer portal or a simple web app is, and this is often where the savings are biggest, because the calls and emails stop. I've compared building a portal with buying one in custom vs white-label customer portals.

10. Your process runs on colors and reminders

Yellow means pending, green means approved and red means someone needs to call the customer. Reminders live in Outlook, approvals happen by email, and the full picture exists only in the head of whoever has been paying attention. The spreadsheet has become a workflow system (a tool that controls who does what, and when) without anyone deciding it should.

A cell color can't send a reminder or stop someone from skipping a step. Software can, with statuses, fixed steps and automatic emails when something has been waiting too long. Before you build anything, map the process properly. My guide to digitizing manual business processes shows how.

11. Monthly reporting takes a full day

Every month someone pulls figures from five sheets, fixes the formatting, builds pivot tables and sends a report that's already weeks old by the time management reads it. The bigger the business gets, the longer it takes.

Pivot tables and Power BI help a lot if the data is clean. The report itself is rarely the problem. The problem is that the data is scattered across files in different formats. Once everything lives in one database, reports can be generated automatically and be up to date every morning. You can keep analyzing in Excel. You just export from the software instead of stitching files together by hand.

What replacing Excel costs

The next step isn't necessarily a development project. There are roughly three levels, and the cheapest one that solves your problem is the right one.

Off-the-shelf and no-code tools

If there's a CRM, inventory system or scheduling tool that covers most of what you need, start there. No-code tools like Airtable have a free plan for light use, and the Team plan costs $20 per user per month billed annually, according to Airtable's pricing page. Budget time for setup, data migration and training as well. I've written about where no-code app builders hit their limits, and the wider build-or-buy decision is covered in custom software vs off-the-shelf.

Custom software

A small internal tool with logins, a database, a handful of screens and an import from your spreadsheet typically takes 60-150 hours of development. As one reference point, LønRadar puts senior freelance developers in Denmark at DKK 800-1,200 an hour in 2026, roughly €105-160. That puts a small tool at around €6,000-24,000 excluding VAT. A larger system with user roles, integrations with your accounting and e-commerce tools, and automated reporting often runs to 200-500 hours, or roughly €20,000-80,000 and up. Danish rates sit towards the upper end of the European range, so quotes from elsewhere in Europe may come in lower. Treat these as ballpark figures.

On top of that comes hosting and maintenance. My rule of thumb is to budget 10-20% of the build cost per year. For a full breakdown of what pushes the price up or down, see my guide to software development costs.

Compare it with what the spreadsheet costs you now

Weigh the price of software against what the spreadsheet already costs. A worked example: three people each spend four hours a week copying, fixing and checking data. That's 12 hours a week, or about 550 hours a year over 46 working weeks. At an internal cost of €50 an hour, deliberately on the low side, that's around €27,500 a year before you count the errors. Even if a €20,000 tool only removes half of that time, it pays for itself in about a year and a half.

When to stay in Excel

Excel is an excellent tool, and plenty of businesses move off it too early. Stay with the spreadsheet if one or more of these apply:

• It's you and two or three colleagues using it, and the data rarely changes.
• The job is analysis, budgeting or scenario planning, where flexibility is the whole point.
• The process still changes week to week. Build now and you'll be building for a workflow that won't exist in three months.
• An off-the-shelf product fits. Then buy it, even if that means you don't need someone like me.
• Nobody on your team has time to be involved. Software built without input from the people who'll use it tends to get replaced by a new spreadsheet.

Excel doesn't disappear when the software arrives, either. Good custom software lets people export to Excel and run their own analysis. The difference is that the spreadsheet is no longer where the real numbers live.

How to move from spreadsheets to software

If you've recognized enough signs to take the next step, this is the order I'd recommend:

1. List the spreadsheets your business can't do without, and who uses each one.
2. For each sheet, write down what it's used for, where the data comes from and where it goes next.
3. Estimate how many hours a week go into copying, checking and reporting. That number is your benchmark.
4. Pick a level: cleanup, off-the-shelf or custom software.
5. Start with one process, not the whole company. Move it, learn from it, then tackle the next one.

For larger projects I start with a paid, fixed-price discovery phase, where I map the process and the data with you and finish with a plan and a quote. You work directly with me as the developer throughout, and you own the code from day one. You can see how I approach this kind of work on my page about web apps and platforms.

Frequently asked questions

Should we try Microsoft Lists or Power Apps before custom software?+

If you already pay for Microsoft 365, it's worth a look. Microsoft Lists can replace a simple shared tracker, and Power Apps can handle basic forms and approvals. Check the licensing first, as some Power Apps features need extra licenses. Once you need complex business rules, integrations or access for customers, you'll usually hit the limits quickly.

How long does it take to migrate data out of Excel?+

The import itself is rarely slow. The time goes into the cleanup beforehand: duplicates, customers spelled three ways, dates stored as text and columns that mean different things in different sheets. Set aside time to go through the data with the people who know it, and import into a test environment before you go live.

Can new software run alongside our spreadsheets for a while?+

Yes, and it's often a sensible transition. The software can import the sheets that are still in use, and people can export from the software back to Excel. That way nobody has to switch on the same day. In the long run, though, the software should be the only place where data is edited, or you end up with two versions of the truth.

Can't AI tools just fix our spreadsheets?+

AI tools such as Copilot in Excel can help with formulas, summaries and cleaning up data. That makes the spreadsheet better, but it doesn't solve the underlying problems: one file, no per-user permissions and no history per record. Use AI to tidy the data before you migrate it, but don't expect it to replace proper software.

Who owns the software once it's built?+

Your contract should settle that. When I build something, you own the code from day one. Whoever you hire, make sure the rights are transferred to you, the code lives in your own repository and you have access to the database and the hosting, so you're never locked into a single supplier.