In 2023 we wrote about how smart locks would "revolutionise" the sector. Three years on they are no longer an innovation: they are the minimum standard. This is the 2026 version — with the brands that survived, real PMS integration, and why Spanish regulations now make them all but compulsory.
Why they stopped being optional
In 2026, check-in with a physical key has three problems that compound each other:
- Operating cost: every key handover and collection costs between €15 and €30 in staff time. With 200 bookings a year, that is €3,000-6,000 in key logistics alone.
- Risk of loss: a lost key means changing the cylinder. €80-150 per incident. It happens more than you think — especially with groups.
- Identification rules: RD 933/2021 requires the guest to be registered at check-in. With a smart lock the guest has to send you their ID document BEFORE you give them the code. With a physical key it is far easier for it to end up with someone who is not the registered guest.
How they work in 2026
Three components:
- Hardware: the lock itself. It replaces the cylinder or mounts over the existing one. Connectivity: WiFi, Z-Wave, or both.
- Management platform: where you generate temporary codes. It usually integrates with your PMS (Hostaway, Guesty, Smoobu) or directly with Airbnb.
- Backup: ALWAYS — an emergency physical key plus an alternative master code. If the WiFi or the battery fails, you do not want your guest stuck outside.
What we use at MyRentalHost
TTLock + Tuya with a WiFi module
This is what we install today in the flats we manage in Barcelona and Madrid. It is not about the owner's budget — it is our choice, based on the operational reality of professional management:
- Zero fixed costs for the owner. No monthly subscriptions for API access, no premium licences. Nuki Pro, for example, charges a subscription to access its Web API. Across a portfolio of 20 flats × 12 months × several years, that fee adds up and eats into returns for no reason.
- Open API = direct integration with our PMS. No extra licences, no dependency on the manufacturer's app. We generate codes when a booking is confirmed, invalidate them on cancellation, and audit every access. All automatic.
- Years of real deployment with consistent results. We have tested them in heavily used flats, in reinforced cylinders, with mediocre WiFi — and they hold up. Tuya's Spanish-language support actually works.
- Value for money that speaks for itself. €90-150 installed, against €230+ for the premium ones with a subscription. The difference is not looks or durability — it is the manufacturer's business model.
For us, a smart lock is infrastructure, not a luxury brand. It has to be reliable, integrable and fair on the owner's pocket. TTLock + Tuya ticks all three.
Why this model and not the subscription one
In short-term rental, the owner's margin is defended in the details. A flat with €4-12/month in lock subscriptions, multiplied over years, is hundreds of euros that never come back. And if you manage more than one flat, multiply again.
The premium smart lock industry (Nuki Pro, August, Linus) has a good product, but its business model leans more and more on the monthly API fee. For an individual owner with a single flat, that may go unnoticed. For a manager with a portfolio, it is the difference between a sustainable system and a silent drain.
If your priority is premium looks or a recognised brand — Nuki is a valid option and we will say so without hesitation. We prioritise something else: no pointless recurring cost, direct integration, full operational control. We made that call coolly, after testing the four main alternatives in real flats.
Other options on the market that also work
For transparency, the alternatives worth considering — each has its place depending on your priorities:
Nuki Smart Lock 4 Pro
The European premium option. Very refined design, excellent app, solid Spanish support. Worth it if you value those three things and the Web API subscription suits you. Price: €260-320 + a monthly fee for advanced integration.
August / Yale Linus L2
A solid product, very popular in English-speaking markets (UK, US). High build quality. Spanish-language support is a little weaker than Nuki's. Price: €230-280.
Igloohome (offline codes)
Unique in its category: it generates codes that the lock validates without needing WiFi. If your flat has patchy wireless coverage or sits in an area with a lot of interference, it is the safe bet. Pricier: €260-350.
Integration with your PMS
Without integration you are generating codes by hand for every booking. Once you reach 20-30 bookings a month, that is half a working day of manual labour. With real integration:
- New booking on Airbnb → the PMS receives it → generates an automatic code for those dates → sent to the guest 24 hours before check-in
- Cancellation → the code is invalidated instantly
- Audit trail: every use of the code is logged with a timestamp (useful when something goes wrong)
What changed with the Spanish regulations
Since RD 933/2021 and its 2024 updates, more guest data has to be collected and transmitted within a short deadline. With a smart lock, the flow is:
- Booking confirmed → the guest receives a link to upload their ID or passport plus their details.
- Data verified (manually or automatically) → transmitted to the authority.
- Only then is the access code released.
This closes off the "I book in my name but someone else goes in" case — which was hard to control with a physical key and is now a legal obligation to verify.
Costs and ROI
- €110Average cost of TTLock + Tuya installed (BCN/MAD)
- 3-5 monthsTypical payback vs. key logistics
- −70%Reduction in reported access incidents
- +0.2Average rating increase on Airbnb after the change (MRH data)
Mistakes we see from self-managing owners
- Not testing the lock with every code before the first guest. Test it by generating a code of your own and letting yourself in.
- Having no plan B. No emergency key, no alternative master code, no local contact. When it fails, it will be at 11pm on a Sunday.
- Buying the cheapest one. A €40 lock that freezes twice a season costs more than a €250 one that always works.
- Linking it to the flat's WiFi. If the guest resets the router, you lose remote access. Better: a dedicated SIM or the building's own WiFi.