Keep an eye on your flat
without being there.

Not while it's let. For the duration of the tenancy, the flat is the tenant's home in every sense, even though you own the property, and recording inside it is not allowed under any circumstances: not the living room, not a shared kitchen, and certainly not a bedroom. That protection doesn't depend on whether or not you trust whoever lives there; it's a right that can't be negotiated away in the tenancy agreement. What you can legitimately monitor are the areas used exclusively by you as the owner: the entrance to the building, the landing if it's private, or a storage room or garage that isn't part of the let property. That monitoring must be flagged with a visible sign before anyone enters the recorded area, and the cameras must point only at those areas, never angled towards the flat's windows or terraces. It's the difference between watching your property and watching your tenant, and only the first is legal.

The type of contract changes, but the underlying principle doesn't: while someone is living in the property, whether for a year or a weekend, the inside remains their private space and can't be recorded. The only thing that changes with a seasonal let is how often new people come in, which in practice makes code-based entry even more useful than cameras inside the flat: each guest gets in with their own code and there's no need to arrange key handovers every few days. Where you can monitor is the entrance to the building or the flat, with the appropriate sign, just as with a long-term let. Many holiday-let listings now include a notice about cameras outside the property for exactly this reason: telling guests before they book means nobody gets an unpleasant surprise on arrival, and it also heads off complaints afterwards.

Yes, always, and it's best to do it in two ways at once: with the information sign visible in the monitored area, which is mandatory, and in writing before the tenant moves in, ideally as a clause in the tenancy agreement itself explaining what is recorded and what isn't. The sign satisfies data protection rules, but the written notice is what really prevents conflict: if the tenant knows from day one that the camera is at the street door and not inside the flat, there's no room for doubt or mistrust later on. Telling them up front heads off the vast majority of the friction this issue tends to cause, because most of it doesn't come from there being a camera, but from the tenant finding it on their own and wondering what else they haven't been told. A clear notice from the start is not only a legal requirement but also the cheapest way to spare yourself that problem.

It depends on how the system was installed. A system designed for a rental flat, which may sit empty for weeks, shouldn't rely entirely on the power never failing: with a small backup supply at the key points, cameras and router can ride out a short outage without stopping recording or sending alerts. What makes the difference isn't just that backup supply, but also how the system is wired: one with cameras connected by network cable, rather than relying solely on Wi-Fi, tends to be more stable during micro-outages and easier to power centrally from a single point. With an alert set up on your phone, you also find out about an outage the moment it happens, instead of discovering it weeks later when you check the recordings and find an unexplained gap. You can see this comparison in Wi-Fi cameras or wired cameras.

What decides the number isn't the size of the flat, but how many ways in and out the building has and which area is your responsibility as the owner. A street door with a single entrance and no extra common areas can be covered by one well-placed camera; a building with a garage, storage room or several secondary entrances needs each of those points covered for the monitoring to make sense, because a single camera pointed at the main door misses every other way in. It also matters whether you just want to see who comes in or also identify faces and number plates clearly, because that determines where and at what height each camera goes, not just how many there are. The sensible approach is to start with the entrances that genuinely concern you, rather than copying a standard package designed for a building that isn't yours. You can read more about it in how many cameras you really need.

It depends on what problem you want to solve. A camera lets you see and record what happens, but on its own it doesn't alert you that something is happening right now unless motion detection is set up, and even then the alert comes after the event. An alarm with sensors is designed for exactly the opposite: detecting unauthorised entry the moment it happens and alerting you instantly, before there's anything to regret. In a rental flat, where the biggest risk isn't usually a burglary but someone getting in outside the agreed dates or a guest who doesn't leave when they should, combining the two usually works better than either on its own: the camera documents and the alarm alerts you in time. If you can only start with one, the usual approach is to prioritise according to what worries you most in your particular case. We go into this in alarm or camera: which to install first.