The Hidden Costs of a Landlord Spreadsheet (UK, 2026)

The Spreadsheet Problem

The short answer: a spreadsheet is enough for one property you know well, with income under the Making Tax Digital threshold. From a second property, or once Making Tax Digital applies to you, software that warns you before a date passes, and sends your quarterly updates from the same records, does a job a spreadsheet cannot do on its own.

Plenty of UK landlords run their lets from a spreadsheet: the properties, the certificate dates, the tenants, the rent in and the costs out. Excel and Google Sheets are free, familiar and flexible.

The catch is that spreadsheets are passive. They show you data. They don't tell you when something is about to go wrong. They don't send you a reminder at 11pm on a Tuesday when you've forgotten to book your annual gas inspection. They don't warn you that your EICR at 7 Oak Avenue expires next month.

What Spreadsheet Landlords Miss

Here are the most common compliance failures that happen to spreadsheet users:

Lapsed Gas Safety Certificate

Easy to miss. The check is due every 12 months. You're busy. The date slips past. Missing the annual gas safety check is a criminal offence, and the fine is unlimited. It used to stop you serving a Section 21 notice too. Section 21 ended for private tenancies on 1 May 2026; the offence didn't.

Expired EICR

It's a 5-year cycle. With multiple properties, it's genuinely hard to track without automation.

Deposit protected late

The 30-day window feels generous until a new tenancy, a house move, a busy week at work, and suddenly it's day 35.

Right to Rent not followed up

If a tenant had time-limited right to rent status, you should have rechecked it. Did your spreadsheet remind you? Probably not.

What Landlord Software Does Differently

Software like LetCompliance doesn't just store the data. It acts on it:

Automatic reminders: You're told 90, 30, 14, 7 and 1 day before any certificate expires, by email (or by text on a paid plan), instead of relying on you to open a spreadsheet.

Live compliance score: Every property gets a 0 to 100 score updated daily. Open the app and in 3 seconds you know which properties need attention.

Section 8 notice builder: Choose the grounds and it writes the Schedule 2 wording, works out the notice period and checks the Ground 8 arrears threshold against your rent ledger.

Document vault: All certificates stored in one encrypted place, filed by property, type and date, and each certificate's expiry date is read off it when you upload it. No more hunting through email archives.

Profitability calculator: Know your actual monthly net profit (or loss) per property, not just rent minus mortgage.

The Cost Comparison

LetCompliance Portfolio plan: £19 a month (up to 10 properties)

Five years of it: £1,140

A spreadsheet: free to open, plus bridging software once Making Tax Digital applies to you, plus the evenings spent keeping every date current by hand.

What the plan buys is the warning before a date passes, and one set of records that your tax figures come from.

If a date is missed: the penalties

These are the maximums the law allows, not automatic fines. Whether anyone acts, and how much is charged, depends on the facts. The deposit points come up only if the tenant goes to court or you need a possession order.

• EICR not in date: a council financial penalty of up to £40,000
• Right to Rent: up to £10,000 per occupier for a first breach, up to £20,000 for a repeat
• Possession on hold: while a deposit is unprotected, or the deposit paperwork (the Prescribed Information) was never given, the court cannot make a possession order on most grounds (Housing Act 2004, section 215), and the arrears keep growing until it is put right
• Deposit protected late or not at all: if the tenant claims, the court must order 1 to 3 times the deposit (Housing Act 2004, section 214)
• Unlicensed HMO: an unlimited fine + Rent Repayment Order (up to two years’ rent for offences from 1 May 2026)

Most landlords who get fined are not cavalier about compliance. They just didn't have a system that actively caught problems before they became violations.

The argument that changed everything: Making Tax Digital

A spreadsheet-versus-software debate written before 2026 was about convenience. It is not any more, because HMRC now dictates part of the answer.

Making Tax Digital for Income Tax requires landlords in scope to keep digital records and submit quarterly updates to HMRC, then a final declaration, instead of one annual return. The timetable:

• From April 2026: gross property (plus self-employment) income above £50,000. Live now.
• From April 2027: above £30,000.
• From April 2028: above £20,000.

Two things landlords get wrong. The threshold is on gross income, not profit, so a landlord with £52,000 of rent and a heavy mortgage is in scope despite thin profits. And a spreadsheet is not automatically compliant: records must be kept digitally and submitted through compatible software, so a spreadsheet needs bridging software sitting on top of it to file at all.

A salary does not count. Qualifying income is your self-employment and property income before expenses; employment (PAYE) income and pensions are left out. So a landlord with a salary and about £20,000 of rent is measured on the rent alone: over £20,000 on the 2026 to 2027 tax return means quarterly updates from 6 April 2028, and at £20,000 or less no start date has been set.

There is a lot of noise about this, so it is worth reading the MTD myths debunked and why generic accounting apps struggle with property before you buy anything. If you keep a spreadsheet for now, the landlord income and expenses spreadsheet sets one up in the SA105 boxes and the quarterly update categories, with a Transactions tab that saves as a CSV for import.

You can make that work. But at that point you are running a spreadsheet plus a bridging tool plus whatever you use for compliance dates, which is three systems doing the job of one.

What actually breaks, and when

Spreadsheets do not fail dramatically. They degrade.

Version drift. The real one lives on a laptop. A copy goes to the accountant. Somebody edits the copy. Six months later nobody is sure which is current.

Single point of failure. It is on one device, maintained by one person. If that person is ill, on holiday or has left, the portfolio is opaque.

No audit trail. A spreadsheet records that a certificate exists. It does not record when you sent it to the tenant, or that the tenant received it. In a deposit dispute or a disrepair counterclaim, the second thing is the one that matters.

No evidence attached. The invoice, the photograph, the contractor's completion note and the email trail live in an inbox somewhere, not against the property.

It is passive. It shows you data when you open it. It does not act when you do not.

None of these is fatal on one property. All of them compound as you add doors.

The honest case for a spreadsheet

There is one, and pretending otherwise is why software comparisons are not trusted.

If you own one property, you live near it, there is no mortgage, the tenant has been there for years and your income is well under the MTD threshold, a spreadsheet plus a calendar is genuinely adequate. You will spend a few hours a year on it and nothing will go badly wrong.

The point at which it stops working is usually one of four: a second property, a tenancy that goes wrong, crossing the MTD threshold, or handing any of it to someone else. There’s more on the signs it is time to switch, and on MTD when a letting agent collects your rent: the agent’s statement doesn’t do your reporting for you. Most landlords cross one of those without noticing, and only discover the spreadsheet was inadequate at the moment they need evidence.

The alternative, plainly: LetCompliance keeps the rent ledger, the expenses and the certificate dates in one record, sends your Making Tax Digital quarterly updates to HMRC (it's recognised by HMRC for UK property income) and gives you SA105-shaped figures at year end. The columns you were keeping by hand become a by-product. From £7.99 a month, Making Tax Digital included.

If you are leaving the sheet, property portfolio software such as LetCompliance takes it in as a CSV file, and the ranking of UK landlord software shows what each alternative costs.