A spreadsheet is free, and for a single property it can work fine. But most landlords don't stay at one property, and most spreadsheets don't stay accurate. Here's what the real cost looks like once a portfolio grows past the point a spreadsheet can honestly track.
The cost you can't see: missed compliance
A spreadsheet doesn't know your gas safety certificate expires in three weeks unless you built a reminder into it — and kept that reminder maintained every time a certificate renews, a tenancy changes, or a property is added. Most landlords don't discover a lapsed certificate until something forces the issue: a tenant complaint, an inspection, or worse, an incident. The fine for an unsafe gas appliance isn't the real risk — it's the liability if something goes wrong while you were unknowingly non-compliant.
The cost you underestimate: time
Ask most landlords how long they spend each month on admin — chasing a rent payment, checking when the EICR is due, updating a spreadsheet after a maintenance job — and the honest answer is usually "more than I'd like to admit." None of it is individually large. All of it adds up, every month, for as long as you hold the property.
The time cost compounds specifically because a spreadsheet has no memory of its own. It doesn't chase you. It doesn't notice a rent payment didn't land. It doesn't flag that a tenancy is coming up for renewal. Every one of those checks has to happen in your head, on a schedule you have to remember yourself.
The cost that shows up once a year: tax time
Self-assessment season is where spreadsheet drift becomes visible. Expenses logged inconsistently across the year, receipts that were meant to be filed "later," a mortgage interest figure that needs separating out property by property — none of it is hard individually, but reconstructing a year of financial activity from partial records in January is exactly the kind of task that's much cheaper to avoid than to fix.
Making Tax Digital is extending to more landlords over the coming years, meaning quarterly digital record-keeping will become a requirement rather than a good habit for an increasing number of people. A spreadsheet updated in January isn't going to satisfy that.
The cost that's hardest to quantify: fragmented communication
When a tenant messages about a repair over text, a contractor confirms a visit over email, and a note about the conversation lives only in your memory, there's no single record of what was agreed. That's fine until there's a dispute — about whether a repair was reported promptly, whether access was arranged properly, or what a tenant was actually told. A property management platform keeps that history in one place, timestamped, without you having to remember to write it down.
Where the line actually is
None of this means a spreadsheet is wrong for a single property held for the long term with a stable tenant. It means the point where a spreadsheet becomes a liability rather than a convenience arrives earlier than most landlords expect — often around the second or third property, or the first time a tenancy actually goes wrong and you need clean records to fall back on.
Slatebase's Free plan covers up to two properties for exactly this reason — so you can see whether structured tracking actually saves you time before you're relying on it for a portfolio that's too large to manage any other way.