Undeclared Extra Guests: What to Do Without Fines

You go in to clean and there are towels for six on a booking for two. Or the online check-in registers two adults and there are five people with suitcases at the door. It is one of the most common incidents in holiday rentals and also one of the riskiest: maximum capacity, insurance, the guest registration report and, if it turns into a conflict, the review. This guide explains what counts as an extra guest, how to detect it and how to regularise it without ruining the stay or exposing yourself to a fine.

What counts as an extra guest

As a general rule, an extra guest is anyone staying overnight at the property without appearing on the booking. Visits of a few hours are not guests for registration purposes, but remember that they still use services, generate noise and may clash with community or property rules.

Two points that raise frequent doubts:

• Minors and babies: even if some platforms do not charge for them as adults, they take up a place and their details must also be registered. A property's maximum capacity is measured in people, not in paying adults.
• "They'll pay in person": not an exception. If they stay overnight, they go in the record. Payment is a commercial matter; registration is a legal obligation.

It usually happens for three reasons: the guest did not read the listing's capacity, the booking was made for two and more people joined later, or someone simply tried to sneak people in without paying. The right approach is the same in all three cases: detect, regularise and charge with criteria.

Regional fines + insurance + incomplete report

An undeclared guest is not just a revenue problem. It triggers three fronts at once:

• Regional holiday rental rules: each Spanish region regulates maximum occupancy and the consequences of exceeding it, with outcomes ranging from a warning to fines of thousands of euros. It is worth knowing your region's rules and the occupancy you have registered.
• Insurance: many liability or multi-risk policies make cover conditional on the declared occupancy. If a claim arises with undeclared occupants, the insurer may refuse to pay. The most expensive damage is the damage insurance will not cover.
• Guest registration report: registering some guests and omitting others leaves the report incomplete. RD 933/2021 treats filling deficiencies as a minor infringement (€100 to €600), and omitting data or reporting false data as a serious infringement (€601 to €30,000). The platform may also penalise the guest or the host under its unauthorised guest policy.

Obligation to register every occupant

The documentary registration under RD 933/2021 includes every guest in the stay, minors included. Guests over 14 sign their own form, and the data of minors is provided by the accompanying adult, indicating the relationship. The report to SES.Hospedajes must be submitted immediately and, at the latest, within 24 hours from the start of the service.

If your check-in only collects the lead guest's details and leaves the companions as "and family", the report is not complete. The details of what Annex I requires and how to treat each type of guest are in the guide on registration requirements by age, and the general framework of mandatory registration in why every traveller must be identified.

How to detect them: digital check-in (booked vs registered)

The most reliable signal is the mismatch between what was booked and what was registered. On platforms, the booking states a number of guests; your check-in shows the details of those who actually complete the form. When those numbers do not match, you have an incident to resolve before submitting the report.

A digital check-in helps because each occupant submits their own details and the dashboard shows which stays are complete and which are pending. Other useful signals:

• Number of unmade beds, towels and amenities consumed at cleaning.
• More rubbish and bottles than reasonable for the declared occupancy.
• Neighbour complaints about noise or access.
• Cameras in common areas, if you have them: remember they can only film common areas, with an information sign, and they do not replace guest registration.

Check the mismatch before every submission. It is a thirty-second control that prevents two problems: the incomplete report and the argument with the guest two days later.

Step by step: contact, regularisation and charging

1. Cross-check the information. Booking, registered guests and the actual state of the property. Write down what you see, with date and time.
2. Contact the lead guest in a neutral tone. Assume good faith: "To complete the legal registration I need to confirm how many people are finally staying". Avoid accusations that put them on the defensive.
3. Explain the supplement and how it will be charged. If the booking came through a platform, the usual route is to amend the booking or send a money request; for direct bookings, apply the supplement agreed in the contract or house rules.
4. Ask for the new occupants' details and register them. Without data there is no regularisation, neither in the dashboard nor in the report.
5. If they refuse to declare, do not turn it into a face-to-face conflict. Document the conversation, state that registration is mandatory and weigh your options under your contract and platform policies: regularise with what you have, report the case or, where applicable, end the stay in line with the applicable rules.
6. Keep a record. Messages, decisions and dates. If a claim arrives tomorrow, that paper trail is your version of events.

Update the report before submitting

If you have not submitted the report yet, the correction is straightforward: add the new guests to the stay and submit the complete report within the deadline. In BnCheck you will find the steps in the guide on adding extra guests to a stay.

If the report has already been submitted, it must be corrected: never fill in invented data to make the numbers match. A stay with more people than were reported, found in an inspection, is exactly the kind of incident that turns a minor fine into a bigger problem. The procedure for correcting a report already filed is in the guide on SES errors and correcting guest reports.

Prevention: house rules and deposit

• Maximum capacity visible in the listing, with the exact occupancy and what happens if it is exceeded.
• An extra guest supplement defined and published, so you can charge it without an argument.
• Mandatory check-in for every occupant before arrival: the cleanest way to register everyone from minute one.
• A deposit where the platform or your direct booking terms allow it, as a fallback for damage with over-occupancy.
• A welcome message reminding guests of the rules and thanking them for cooperating with registration.
• A quick mismatch check before submitting each report, as part of the check-in process.

When over-occupancy causes damage, the claim criteria are the same as for any other damage: document it, cross-check booked against registered guests and use that mismatch as evidence. It is covered in the guide on claiming damage on Airbnb.

Informational article on registration and capacity in holiday rentals. Regional amounts and sanctions vary by region; check the rules applicable to your property or consult an adviser for specific cases.