Can a British grandson join grandparents resident in Spain for a summer as a dependent?

Because your grandson is 19 years old and a British citizen, the situation is a bit different than if he were a minor.

Let’s break it down clearly:

As a British Citizen (Post-Brexit)

He is now considered a non-EU national in Spain.

He can:

Stay in Spain up to 90 days within any 180-day period without a visa (tourist stay).

He cannot work during this 90-day tourist stay.

So if he simply wants to stay with you May–August (up to 90 days) and not work, he does not need a visa.

But if he wants to work, he cannot do so as a tourist.

Can You Apply for a Dependent Visa for Him?

Unfortunately, almost certainly no.

Spanish family reunification rules allow you to sponsor:

Spouse or partner

Children under 18

Adult children only if financially dependent and with special circumstances (e.g., disability)

Dependent parents (in some cases)

A 19-year-old grandson does not qualify as a dependent under normal Spanish immigration rules.

Grandchildren are not typically eligible unless there are exceptional legal guardianship circumstances.

Important Question: Does He Have French Residency?

Since he has lived in France for 8 years, this is key:

If he has long-term French residence status, he may have more mobility rights.

But unless he has French citizenship (EU), he still needs authorization to work in Spain.

If he becomes a French citizen → he would have full EU freedom of movement and could live and work in Spain freely.

If He Wants to Work Legally in Spain (Short Term)

There are limited options:

Option A: Student Internship Agreement

If his university arranges:

An internship agreement

Through a Spanish company

As part of his studies

This can sometimes be authorized under student mobility rules.

Option B: Work Visa (More Difficult for 3 Months)

He would need:

A Spanish employer

A work contract

Employer sponsorship

Application processed before starting work

For a short 3-month summer job, this is usually difficult.

Practical Reality

For a 3–4 month summer stay:

He can stay up to 90 days as a tourist.

He cannot legally work.

You cannot sponsor him as a dependent.

If working is essential, he would need proper work authorization arranged in advance.

Official sources: Ministry of Inclusion: temporary residence through family reunification (who can be reunified) and EU: what is the EES (short-stay 90/180 rule)