How football transfers work

In one lineA transfer moves a player’s registration from one club to another, usually for a fee, under rules written mainly by FIFA and shaped in Europe by EU law.

The basic idea

A professional player is registered to a club through a national football association. A transfer moves that registration to a new club. If the player is still under contract, the new club normally pays the old one to release the player early. That payment is the transfer fee; FIFA’s rules call it “transfer compensation”.

The rulebook is FIFA’s Regulations on the Status and Transfer of Players (RSTP). National associations apply it and add their own rules for domestic moves. This guide describes the rules in force in September 2026.

Windows: when players can be registered

Players can only be registered during two registration periods a year, usually called transfer windows. Each association sets its own dates, within FIFA limits:

• the first period, around the start of the season, lasts between 8 and 12 weeks;
• the second, in mid-season, lasts between 4 and 8 weeks;
• together, they may not exceed 16 weeks.

Associations must enter their dates in FIFA’s system at least 12 months ahead. There are narrow exceptions. For example, a player whose contract expired, or was ended by mutual agreement, before the window closed may still be registered after it shuts.

The paperwork: TMS and the ITC

International transfers run through FIFA’s Transfer Matching System (TMS), a web-based platform. Each club enters the details separately — player, contract dates, fee and payment schedule. The two sets of entries must match, and the clubs have to resolve any mismatch before the move can go through.

The new association then needs an International Transfer Certificate (ITC) from the player’s old association. Without it, the player cannot be registered abroad. The ITC is free of charge and cannot be made conditional. Since 1 January 2025, the old association must deliver it within 72 hours of the request. If it does not respond, the new association may register the player anyway, and a contract dispute can no longer hold the certificate back.

How fees are structured

TMS asks clubs to declare which kinds of payment a deal involves: a fixed fee (with any instalments), a release or buy-out fee, a conditional fee, and a sell-on fee.

• Instalments spread a fixed fee over months or years.
• Add-ons are conditional sums paid only if targets are met, such as a number of appearances.
• Sell-on clauses give the selling club a percentage of any future fee. FIFA bans agreements that give an outside party a share of a player’s future transfer fees (known as third-party ownership). A player’s former clubs, however, do not count as third parties, so sell-on clauses between clubs are allowed.
• Buy-back clauses let the selling club re-sign the player later for a fee fixed in advance.

Loans: option or obligation

A loan moves a player to another club for a set period. The contract with the original club is suspended during the loan unless the parties agree otherwise in writing. Under the RSTP:

• a loan lasts at least the time between two windows and at most one year, and can be extended within those limits with the player’s written consent;
• the borrowing club may not loan the player on or sell them to a third club;
• since 1 July 2024, a club may have at most six professionals loaned out and six loaned in at any one time during a season;
• separately, a club may have no more than three professionals loaned to, or borrowed from, any single club at one time.

Young players trained by the lending club are exempt from the limit of six if the loan starts before the end of the season in which they turn 21. The limit of three still applies.

Many loans include a purchase clause:

• an option to buy lets the borrowing club make the move permanent for a pre-agreed fee, but it does not have to;
• an obligation to buy makes the move permanent automatically once agreed conditions are met, such as promotion or a set number of appearances.

FIFA’s commentary on its rules gives both as examples of clauses that do not count as banned outside influence over a club.

Release clauses

A release clause is a price written into a player’s contract. If it is paid, the player may leave without the current club’s agreement. In Spain, such clauses rest on employment law. Royal Decree 1006/1985, which governs professional athletes’ employment, says that when an athlete ends a contract early without cause attributable to the club, the club may be entitled to compensation. That amount can be agreed in the contract; otherwise the labour courts set it. In Spanish football, the agreed figure is known as the cláusula de rescisión.

Free transfers and pre-contracts

On 15 December 1995, in the Bosman case (C-415/93), the Court of Justice of the European Union ruled that EU free-movement law rules out requiring a fee when an out-of-contract EU national moves to a club in another member state. The same judgment struck down limits on how many players from other member states a club could field. Since then, a player whose contract has ended can move without a transfer fee — a free transfer. Training compensation may still be owed for younger players, as explained below.

The RSTP also lets a player sign with another club once the current contract has expired or has six months or less to run. This is often called a pre-contract. A club that wants to sign a player must tell the player’s current club in writing before starting negotiations.

Money for the clubs that trained the player

Training compensation is due when a player signs a first professional contract, and each time a professional moves between clubs in different associations until the end of the calendar year of their 23rd birthday. It covers training between the ages of 12 and 21, and is owed even if the move happens at the end of a contract. It does not apply in women’s football.

The solidarity mechanism applies when a player moves during a contract. Five per cent of the fee is set aside and shared among the clubs that trained the player between the calendar years of the 12th and 23rd birthdays. Each year from age 12 to 15 earns 5% of that pot; each year from 16 to 23 earns 10%. It applies to international moves, including loans, and to domestic moves when a training club belongs to another country’s association.

Example: on a fee of 20 million, the pot is 1 million. A club that trained the player in the years of the 16th, 17th and 18th birthdays receives 30% of the pot, or 300,000.

The Diarra ruling and FIFA’s response

On 4 October 2024, in Case C-650/22 (Diarra), the Court of Justice of the European Union examined FIFA rules that applied when a player ended a contract without “just cause”. Under those rules, the player’s new club was jointly liable for any compensation and could, in some cases, be banned from registering new players, while the old association had to withhold the ITC while a dispute was pending. The Court held that these rules were contrary to EU law on free movement of workers and on competition. The final decision on the case was left to the Belgian court that had referred it.

FIFA responded with an interim framework, approved on 22 December 2024 and in force from 1 January 2025. It:

• defined “just cause” for ending a contract;
• changed how compensation for breach is calculated;
• made a new club liable, or open to sanctions, only if it is shown to have induced the breach;
• introduced the 72-hour ITC rule described above.

On 10 June 2026, the Bureau of the FIFA Council approved a new version of the RSTP, negotiated with representatives of players, clubs and leagues. It is due to enter into force on 1 January 2027.

Where to go next

• Football agents and FIFA’s agent rules — who represents players and clubs in a transfer, and how they are paid.
• Football’s spending rules, explained — the financial rules that shape how much clubs can spend on transfers and wages.

Key terms

• ITC — International Transfer Certificate; the release document between associations.
• Sell-on clause — a share of a player’s future fee kept by a former club.
• Solidarity mechanism — 5% of a fee shared among training clubs.