Excel vs leave management software: an honest 2026 comparison

Excel vs leave management software at a glance

The honest version of the side-by-side, with no marketing gloss. Yes/no scoring is based on the typical out-of-the-box experience: a homemade spreadsheet on one side, a UK leave management tool in the £1 to £5 per-user range on the other.

The total cost of ownership: what Excel actually costs you

The headline price of a spreadsheet is zero. The total cost is not. Total cost of ownership for an HR system has four parts: licence cost, admin time, error cost, and risk cost. Spreadsheets save on the first and accumulate the rest.

1. Admin time

The work the spreadsheet pushes onto the admin is the easiest cost to ignore and the largest in pounds. For a typical UK SME of 15 people, the recurring admin involves: receiving and approving requests over email, transcribing them into the file, recalculating remaining balances, fielding questions about "how many days have I got left," reconciling the file when someone joins or leaves, copying numbers into payroll once a month, and re-checking the file when a balance is disputed.

Two to four hours a month is a fair estimate for a team that size. At a fully-loaded admin cost of £30 per hour, that is £60 to £120 a month · before any error cost or risk cost. The same team on dedicated leave software at £1 per user per month costs £15.

2. Error cost

Spreadsheets are error-prone. The often-cited figure is that around 88% of spreadsheets contain errors, mostly from manual entry and copy-paste. For leave tracking, the errors that matter are: pro-rata calculations done wrong for part-time joiners or leavers; bank holidays double-counted or missed; rolled-up holiday pay done at the old 12.07% multiplier where it now needs to be the post-April 2024 method for irregular hours workers; and the simple case of a balance cell that was overwritten and never reconciled.

An incorrect leaver balance is the costly one. If an employee leaves and the spreadsheet under-calculates their accrued holiday by even two days, you owe them their daily rate twice over (or more, if it goes to a tribunal). For a single mistake on a £35,000 salary, that is roughly £269 in pay-in-lieu plus any tribunal cost if it ends up disputed. The full mechanics of getting this right are in our leaver entitlement calculation guide.

3. Risk cost (GDPR)

This is the cost most people genuinely underestimate. We give it its own section below, because the ICO has done the small businesses of the UK a favour by making the position unmissable.

4. The honest counter-cost: subscription drift

Software has its own real cost: per-user pricing means your bill grows as your team does. A 50-person team paying £3 per user per month is £1,800 a year, which is more than most people would spend on Excel admin. The economics flip again at the very top of the SME range, where dedicated tools start to look pricey relative to a well-built spreadsheet maintained by a senior office manager who also has other duties. We come back to this in the "when Excel is genuinely the right answer" section.

GDPR and the ICO's view of HR spreadsheets

Staff leave records contain personal data. Sickness absence records, where you keep them, can contain special category data (information about health). Under UK GDPR you are required, under Article 5(1)(f) and Article 32, to use "appropriate technical and organisational measures" to keep that data secure. The law is technology-neutral. It does not ban spreadsheets. It asks whether your tools and processes deliver appropriate security · and that is where Excel struggles.

The ICO's position

The clearest UK signal is the Information Commissioner's Office's £750,000 fine of the Police Service of Northern Ireland in October 2024. The breach was triggered by a single Excel file: a hidden worksheet tab, missed during quality assurance, was published online with the names, ranks and roles of 9,483 staff. The ICO calculated a starting penalty of £5.6 million and reduced it to £750,000 only because public sector enforcement guidance limits fines on public bodies. A private company would have faced the full £5.6 million.

The Commissioner's words after the case were unusually direct: "Let this be a lesson learned for all organisations. Check, challenge and change your disclosure procedures to ensure you protect people's personal information." A second case the same month · Southend-on-Sea Council, reprimanded for hidden personal data in a spreadsheet sent in response to a Freedom of Information request · underlined that this is not a one-off.

The specific spreadsheet failures the ICO has flagged

From ICO guidance and recent enforcement, the recurring spreadsheet risks for HR data are:

• Hidden tabs and rows. Data hidden inside an Excel workbook is still in the file. It survives email, attachment, FOI response, anything.
• Pivot tables and source data. Pivot tables retain the underlying data. Sharing a workbook with the pivot but "deleting" the source sheet does not always remove the data.
• Metadata and document properties. Author names, comments and revision marks travel with the file.
• Email forwarding and chain copies. Once a holiday tracker is emailed to a manager, you have no record of where the file went next.
• Shared drive sprawl. The same data sitting in three places · SharePoint, OneDrive, a personal laptop · means three places to secure and three places where a subject access request needs to look.
• No audit trail. Spreadsheets do not record who looked at the file, only who last edited it. The ICO's accountability principle requires you to demonstrate compliance, which is hard with no log.

None of these are insurmountable. They just require deliberate work that few small businesses actually do. A dedicated leave management tool removes most of them by design · the data is not a file, role-based permissions decide who sees what, and changes are logged.

What breaks at 5, 15, 50 and 100 employees

The case for Excel weakens predictably as the team grows. Here is what tends to give way at each rung.

5 employees: spreadsheets work

At this size, one person owns the file, the team sees each other every day, and a one-line message is faster than any approval workflow. The spreadsheet is not a system, it is shared notes. Leave software at £5 per month for the whole company is still cheap, but it is not solving a problem you actually have.

15 employees: the real switching point

This is where a useful sequence of pressures starts to compound. People want to check their balance without asking. Half-days come up. The team has its first part-timer, and the admin discovers that working out 5.6 weeks of holiday for a 3-day-a-week worker is not as simple as they thought (it is 16.8 days). Two people both ask to take the same week off. A leaver disputes their final pay calculation. Each event is an hour or two of admin work and an unsettling reminder that the spreadsheet is not really set up for this.

50 employees: spreadsheets start failing in compounding ways

By here, you almost certainly have separate departments with their own managers, capacity limits ("no more than two engineers on leave at once"), and custom leave types beyond annual leave · sickness, maternity, jury service, bereavement. A spreadsheet can in theory handle all of that. In practice, the formulas start to break, and one person quietly becomes the spreadsheet's sole maintainer. They become a single point of failure for the company's entire HR record-keeping.

100+ employees: most have already moved

At this size, the GDPR exposure alone usually settles it. The discussion is no longer Excel vs software; it is dedicated leave tool vs full HRIS. If leave is the only thing you need to digitise, a focused tool is dramatically cheaper than a CharlieHR or BambooHR-class platform. If you also need contracts, performance reviews, payroll integration and onboarding, you want the full HRIS.

When Excel is genuinely the right answer

If we are being honest, Excel is the right call for a real, if narrow, set of situations. Anyone who tells you spreadsheets are always wrong is selling something. The cases where Excel beats dedicated software cleanly are:

• Very small teams (around 5 people or fewer) with one admin who already lives in Microsoft 365 or Google Workspace. The marginal cost of staying is genuinely zero.
• Highly bespoke calculations · for example a hospitality business with a dozen casual staff on rolled-up holiday pay, an accountant who already has the formulas right, and no need for self-service. Most leave software does not natively model 12.07% accrual against actual hours worked.
• One-off projects or short-term staff where the admin overhead of setting up a tool is more than the saving.
• Companies in a transition year where you know you are about to roll out a full HRIS in six months and a stop-gap is fine.
• Heavily regulated environments with their own internal audit tooling · some legal and financial firms keep leave inside their existing GRC platform rather than adopt a separate tool, and a spreadsheet feeding that platform is a sensible bridge.

Outside those situations, the trade tilts pretty quickly. The interesting question is rarely "can a spreadsheet do this" but "is the admin willing to do the work to keep the spreadsheet correct, year after year, as the rules change." The April 2024 reforms to holiday pay for irregular hours workers, the day-one paternity leave change in April 2026, and the new neonatal care leave entitlement all required spreadsheet templates to be rebuilt. Software updates handle that for you.

The 6 questions to ask before switching

If you have decided to evaluate dedicated leave software, the questions worth asking before you commit are these. The first three are about features, the last three about the relationship.

1. Does it support the working patterns you actually have? Most tools assume a uniform full-time week. If you have part-timers, term-time-only staff, or shift workers, check that the tool lets you set custom annual allowances per person rather than only at company level. A tool that cannot give a 3-day-a-week worker their 16.8-day allowance separately from a full-timer's 28 is a tool you will fight every year.
2. Are UK bank holidays handled correctly? The right answer is automatic, region-aware (England & Wales, Scotland and Northern Ireland are different), pulled from the official GOV.UK feed, and never deducted from the personal allowance. If a tool asks you to type bank holidays in manually, that is a tool built for a different country.
3. Can you create custom leave types beyond annual leave? You will eventually need separate balances for sickness, maternity, jury service, paternity, bereavement and so on. A tool with only one leave type forces you back into a spreadsheet for everything else.
4. Where is the data hosted, and what is the data processor agreement? For UK SMEs the right answer is UK or EU hosting and a clear DPA at the point of signup. Read the sub-processor list. If a tool cannot tell you who else handles your HR data, that is your answer.
5. What is the exit cost? Can you export the whole leave history as a CSV at any time, on a self-service basis, without having to ask for it? If yes, you can leave whenever you want. If no, your data is hostage.
6. What happens at trial end? A genuinely free trial does not require a card up front. Anything that auto-bills on day 31 is a paid trial in fancy dress.

A realistic migration timeline

Switching is faster than most people expect. A 15-person team, with a half-decent existing spreadsheet, can be live on a dedicated tool in well under a working day. The honest sequence:

Total: roughly an hour to two hours of active work. The bigger lift is psychological: persuading the person who built the spreadsheet to let it go. We covered the broader migration question, including how to choose between focused leave tools and full HRIS platforms, in our UK leave management software buyer's guide.

If you are coming off a different tool rather than Excel · specifically Timetastic · the migration question is different and we have a separate, more pointed comparison in our honest Timetastic alternatives review.

Sources

This article cites only primary sources: ICO, GOV.UK, ACAS and legislation.gov.uk.

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