Children, babies and teenagers
Every child staying must be registered, whatever their age. Guests of 14 and over sign for themselves; for younger children an accompanying adult provides the details. The relationship between guests must be given whenever anyone in the party is under 18 — a different age from the signing rule, which is why this causes so much confusion.
Children generate more confusion than any other part of guest registration, and it is easy to see why. Two different ages matter, for two different reasons, and neither is the age most people assume.
The two ages
Fourteen is the age at which a guest signs their own form.
Eighteen is the age below which you must also state how the guests are related to one another.
Neither is an age below which a child stops being registered. There isn't one.
And the next article puts the matter beyond doubt: the record must contain the details in the annexes, including those of children under fourteen.
So a family of four with two small children is four people registered and two signatures.
What if a guest is exactly 14?
They sign. Their 14th birthday is the day it starts.
This comes up constantly, because the Spanish wording — mayor de catorce años, literally "older than fourteen" — looks as though it might mean fifteen and up. It does not, and the decree settles it in its own text.
Article 4.2 puts every guest into one of two groups: those who are mayor de catorce años, and those who are menor de catorce años. There is no third group. A guest who turned 14 last week is plainly not "under fourteen", so they belong to the first group.
The same phrasing governs adulthood in Spain. The Constitution makes Spaniards adults "a los dieciocho años" — at eighteen, meaning from the eighteenth birthday, not from the nineteenth. In Spanish legal drafting, mayor de X años means "having completed X years".
Is a 16-year-old a child or an adult?
For signing: an adult. They sign for themselves.
For the relationship field: a child. Anyone under 18 is a menor de edad in Spain, so their presence means you must state how the party is related.
That split is exactly why the question keeps coming back. Sixteen-year-olds are simultaneously old enough to sign and young enough to trigger the other rule.
Why they ask how you are related
The field exists because a child travelling with adults who are not their parents is exactly the situation the system was built to notice. It is a safeguarding measure, and it is the one part of this that most guests understand immediately once you say so.
A child with no identity document
This is the most-discussed practical problem among owners, and it deserves an honest answer rather than a confident one.
The law asks for a document type and number for each traveller. It does not say what to do when a traveller genuinely has none — and a young child may well have none, particularly a Spanish child, since a DNI is not normally issued until 14.
There is no official guidance on this that we have been able to find. What owners report doing in practice varies: using the child's passport where one exists for travel, using the number from a family book or birth registration, or entering the accompanying adult's details in the relationship field and providing what they can for the child.
We are describing what owners do, not what the law requires, because the law does not address it. If you are regularly hosting families with very young children and want certainty, this is a reasonable question to put to a gestor.
In practice most children arriving from outside Spain hold a passport of their own, because they could not have travelled without one. The problem is much more common with Spanish families.
When the form rejects a teenager
A specific and well-reported fault: a 14-year-old Spanish national is entered, and the form refuses both the DNI and the passport, returns a message about an incorrect date, and demands a valid NIF — a Spanish tax number the child does not have.
Owners also report being unable to clear the date of birth to start the entry again.
This is a validation problem in the form rather than something the law requires of you. If it happens, the practical route is to try the entry again in a fresh session, and if it persists, to raise it with whoever handles your submissions — a provider will have seen it before.
The short version to keep in your head
- Everyone is registered, at every age.
- Fourteen and over sign.
- Under fourteen: an adult gives their details.
- Anyone under eighteen in the party means the relationship field applies.
- A child with no document is a genuine gap in the rules, not something you have missed.