Paris Saint-Germain have signed Neymar from Barcelona after triggering his £198m (€222m) release clause, completing the most expensive transfer in football history. The forward signed a five-year contract and immediately pledged to “conquer the titles” which PSG crave.

“I am extremely happy to join Paris Saint-Germain,” Neymar said. “Since I arrived in Europe, the club has always been one of the most competitive and most ambitious. And the biggest challenge, what most motivated me to join my new team-mates, is to help the club to conquer the titles that their fans want.

Quick guide Neymar and financial fair play Show Hide What is FFP? FFP was introduced by Uefa seven years ago to stop clubs involved in European competition from spending more than they earn. The basic principle is that, beyond a small loss currently set at €5m over three years, clubs’ outgoings must match their incomings. FFP has been deemed a success in curtailing losses sustained by clubs. So what changed? In 2015 it was revised over concerns that the system preserved the status quo, with smaller clubs unable to speculate in the hope of success. Since then, as well as exempting any expenditure on infrastructure or youth development, Uefa has also allowed owners to spend an additional €30m of their own money over a rolling three‑year period. Providing there is a business plan that meets with Uefa’s approval, an owner can exceed the total. What happens if a club are found guilty of an FFP breach? When Manchester City were found to have contravened the regulations in 2014, not only were they fined €60m but they were told that instead of naming a squad of 25 players for the Champions League the following season they could name just 21 with eight of those homegrown. So how do clubs get around it? FFP accounting allows for transfer fees to be paid over the length of the player’s contract. So that gives you a bit of wriggle room – PSG might, for example, be able to sell three or four players at €50m a time during the next couple of years. The Spanish press have claimed that the deal could be done in a more roundabout way. Mundo Deportivo has reported that Neymar may have already agreed to become an ambassador for Qatar’s World Cup and that the fee for this might be around £200m. In that case Neymar would be able to turn up at the offices of La Liga and buy out his own release clause.

“PSG’s ambition attracted me to the club, along with the passion and the energy this brings. I have played four seasons in Europe and I feel ready to take the challenge. From today, I will do everything I can to help my new team-mates, to open up new horizons for my club and to bring happiness to its millions of supporters around the world.”

The Parisians’ president, Nasser Al-Khelaifi, the Qatari businessman who led the acquisition of the Ligue 1 club in 2011, was delighted to get his man.

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“It is with immense joy and pride that we welcome Neymar to PSG,” he said. “Neymar is today one of the very best players in world football. His winning mentality, strength of character and sense of leadership have made him into a great player.

“He will bring a very positive energy to this club. In six years, we have built a very ambitious project that has already taken us to the highest level of national and European football. Today, with the arrival of Neymar, I am convinced that we will come even closer, with the support of our faithful fans, to realising our greatest dreams.”

After a day that saw La Liga officials at first refuse to accept the payment before being urged to “abide by Fifa’s rules” by their French counterparts LFP, Barcelona confirmed they received the payment from the 25-year-old.

“On Thursday afternoon Neymar Jr’s legal representatives visited in person the club’s offices and made the payment of €222m in the player’s name with regards to the unilateral termination of the contract that united both parties,” read the statement.

“As such, the club will pass on to Uefa the details of the above operation so that they can determine the disciplinary responsibilities that may arise from this case.”

Earlier, Neymar’s lawyers Juan de Dios Crespo and Marcos Motta went to La Liga’s headquarters in Madrid to make the deposit but officials, as its president, Javier Tebas, had threatened earlier this week, declined to accept the payment.

“We can confirm the player’s lawyers came to the La Liga offices this morning to deposit the clause and that it has been rejected,” a statement from the league said. “That’s all the information we are giving out at this moment.”

In response, the Ligue de Football Professionnel, which governs the top two leagues in France, called for the matter to be resolved “as soon as possible”.

Tebas has argued the deal would infringe financial fair play and wants to protect Spain’s leading clubs. The transfer is worth around £450m in wages and fees.

Neymar went to Porto on Wednesday for a medical in anticipation of joining PSG, who are aware of the implications of FFP on this transfer and have been working on ways of complying with that. He could now be unveiled on Friday, with preparations already underway in the French capital.

Luis Suárez followed Lionel Messi by posting an Instagram message to Neymar. “My friend I wish you the best in everything that comes!!! Also thank you for your support, for everything that I learned with you and for the unique moments that we spent together!!!! Keep like this and never change love you little bro.”