Is it legal to work for the summer in Spain without work contract

Sadly this is very common.

Risk of heavy fines for you and them if caught

Their way of giving employees no rights and not declaring financial dealings to the authorities.

It is illegal to work without contract,  for 1 minutes it or 3 months.

It happen in special in restaurant but less and less since government is taking care of it more and more.

I hope that finally it will not happens at some point. It is not fear for everyone else that work and pay taxes.

I am so sure that people love free health system,  and when they have a problem they call police, and they use public roads... but they don't want to pay for that.

Please do those of us who are legal and pay all the contributions a favour and report anyone who offers work without a contract to the guardia/police I for one am sick of people who work without paying their dues.

Another thing just for the english community workers who do have a contract, if you are being payed below the minimum wage or on a split contract/cash then there is a place to report it anonymously and they will send someone to the company and check all their books and instruct the pay levels to go up and proper contracts to be given. 

Do not let these businesses scare you with "oh we can't afford it" then close down.  If you work with a proper contract on proper wages throughout the summer then you will be able to claim social income for up to 80% of your wages so it is worth the fight for a contract which means something, what often happens is so much is on contract and the rest cash, this does not benefit you as it means you can't claim when you are not working. Perhaps it is time for people to stop accepting less from their own....

I fully agree with you.How do you report people?

The easiest way is to go to the guardia they will swoop very quickly, if you are working on a contract which is not correct then Servicio Público de Empleo Estatal you can do this anonymously they will come unannounced and go through everyone's work contract hours and pay, they will then enforce change and fine those who are responsible.

This is the law regarding contracts:

Identity of the parties, address of the company and the workplace where the worker performs his duties

Date on which the working relationship starts, category or professional group of the job performed, duration of an ordinary working day and how this is spread out: breaks etc

Amount of initial basic salary and supplements to pay and also when paid (monthly, weekly, etc.)

Number of days holiday and how holiday dates are determined

Period of notice that the employer and employee must give, should the contract be terminated, or at least how this period must be worked out

The collective agreement applicable to the employment relationship, stating the specific features by which it can be identified

Standard working hours in Spain

The organisation of working time in Spain (maximum working hours, rest time, annual holidays, public holidays, paid leave and overtime) is regulated by law, and the working day is regulated by agreement between workers’ and employers’ organisations or in contracts.

Full-time workers in Spain must average a maximum of 40 hours per week of work, calculated on an annual basis.

Workers can’t work for more than nine hours a day unless an agreement is in force

Employees under 18 can only work for eight hours a day across employers, including training

Working hours can be distributed unevenly if a collective agreement is in place

Sick leave

This protects a workers temporarily unable to work and in need of medical assistance due to illness or accident. In such cases the worker will be paid at least 60% income. The employer normally pays the worker this temporary sick pay, and is then reimbursed by the Social Security department. The maximum period of such leave is 18 months, after which the situation must be reviewed.