By the Unity Stays directors, Marcus Chong & Gadir Al-Khatib · Last updated 12 August 2026
In short: Self check-in works through a key safe or, better, a smart lock issuing each booking its own code that expires at check-out. Send instructions before arrival with the full address, photographs of the entrance, the code itself, parking, wifi and a fallback number, rotate codes between stays, and keep a backup key held off-site for failures.
Key safe or smart lock
A key safe is cheap, needs no power and no signal, and works when everything else fails. The downsides are that codes get shared, they are visible to anyone passing, and a stiff mechanism in the dark is a genuine problem.
A smart lock gives each booking its own code, expiring at check-out, with a log of who entered and when. It is materially better for security and for turning over codes. It needs power and usually connectivity, so it needs a battery policy and a physical fallback.
Whichever you use, there must be a way in when it fails. A backup key held locally, and someone who can reach the property, is the difference between an inconvenience and a refund.
What good access instructions contain
Sent before arrival, not on the morning, and written for someone who has never been there and may be arriving in the dark after a delayed journey.
- The full address including the flat number, and which entrance to use if it is not obvious
- Photographs of the door, the key safe or lock, and the entrance from the street
- The code itself, in the message rather than promised later
- What to do if the code fails, with a number that will be answered
- Where to park, specifically, including whether a permit is needed
- Wifi name and password, so they are not hunting for them at midnight
- Heating instructions — the single most common question an operator receives
Late and unknown arrival times
The advantage of self check-in over a small hotel is that arrival time stops mattering. That advantage only exists if the code works from the stated check-in time until check-out, with no collection window and nobody waiting up.
This matters most for the guests who are worth the most: contractors finishing on site, people arriving on delayed transport, corporate bookers whose team lands at different times. A property that cannot take a midnight arrival quietly loses that market.
Set the expectation in the listing too. "Self check-in, any time after 3pm" converts better than a check-in window, because it removes a worry the guest has not asked about yet.
Where it actually goes wrong
Almost never the technology. The failures are procedural, and they repeat.
Instructions sent too late, or sent through a channel the guest is not watching. A code not rotated between bookings, so a previous guest still has access. A flat number missing from the address. A key safe that has stiffened since anyone last used it. A battery nobody was monitoring. Parking described optimistically.
Each of these is fixed by process rather than product, which is why access is one of the things we set up during onboarding and then test rather than assume.