RFID card, app or terminal: how your employees should clock in
We compare the clocking-in methods for employees: mobile app, RFID card, key fob, PIN and physical terminal. Advantages, drawbacks and which to choose for your kind of business.
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Cover photo: an RFID card, a key fob and a clocking-in terminal together on a neutral background (landscape)
An app, a card, a key fob, a PIN or a terminal: there are several ways of clocking in and the best one depends on your business. We compare each clocking-in method so that you can choose the one that fits your team, your premises and your budget.
A mobile app: the most convenient and cheapest
The employee clocks in from their own phone with a button. With geolocation you verify that they are on site. Advantages: no hardware, quick to roll out, allows remote work. Drawback: it requires every employee to have a smartphone and to carry it.
An RFID card: quick and classic
You hold the card up to the terminal's reader and that is it. Advantages: instant, needs no phone, printable with a photo and a name. Drawback: you have to carry the card and replace it if it is lost.
An RFID key fob: for the warehouse and the site
The classic teardrop fob that goes on a keyring. Tough and always on you. Ideal for workshops, warehouses, sites or kitchens, where a phone gets in the way or gets dirty.
🔑 They can be combined
- Nothing stops you using several methods at once in the same company.
- The office with an app, the warehouse with a key fob, reception with a terminal.
- What matters is that they all end up in the same record, reliable and kept for four years.
A PIN on the terminal: nothing to carry
Each employee types their personal code into the terminal. Advantage: nothing to carry and nothing to lose. Drawback: a PIN is easily shared, and a record that anyone can mark on someone else's behalf stops being reliable, which is exactly what the rule requires.
A physical terminal: the clocking-in point on the wall
A device at the entrance where you clock in with a card, a key fob or a PIN. Advantage: a single, visible point, ideal for shifts and a lot of staff. Drawback: it is a purchase (a one-off payment), although it pays for itself quickly.
Fingerprints and facial recognition: the method to rule out
Almost every terminal on the market offers it and it is the one that causes the most problems. Biometric data intended to identify a person uniquely is a special category under article 9 of the GDPR, and processing it is prohibited save by exception. The Agencia Española de Protección de Datos, in its guide on attendance monitoring using biometric systems, concludes two things for working time records:
- To lift the prohibition by way of article 9.2.b) there would have to be a rule with the rank of a statute setting out the use of biometric data for that purpose, «que no se encuentra en la actual normativa legal española» — which is not to be found in current Spanish law.
- The worker's consent is no use either, because of the imbalance between the parties in an employment relationship. And if equivalent alternatives exist — a card, a PIN — biometric processing stops being necessary.
Put practically: if your supplier sells you a fingerprint terminal «to comply with the clocking-in law», they are exposing you to a greater risk of penalty than the one you are trying to avoid. Use a card or a key fob. (The guide is published as the November 2023 version and is marked as under review, so it is worth watching whether the AEPD updates it.)
Note of 4 September 2026: Cairos and clocking in
As of today, 4 September 2026: when this article was written, you still could not see the team's hours in Cairos. Now you can, and it is worth spelling out exactly how, because it is not what people usually assume: Cairos does not clock anyone in. The working time record is kept by ficheo.app and Cairos reads it — read-only — to show those hours next to your invoices and split them by project. A clocking that needs correcting is corrected in ficheo, which is where the record the law requires lives. With your ficheo account connected, that module is not charged separately in Cairos.
See the plans and what they includeWhich one to choose for your business?
- An office or a team with phones: a mobile app.
- A workshop, a warehouse or a site: a key fob or a card.
- A restaurant or a shop with shifts: a terminal at the entrance + a card.
- Never: fingerprints or facial recognition.
- Best of all: combine several according to the job.
Frequently asked questions
Your hours, in the same program that invoices
Cairos does not clock anyone in: the working time record is kept by ficheo.app, and Cairos reads those hours to split them by project and keep them next to your invoices. With your ficheo account connected, the module is not charged separately.