At 23:59 today, 4 September 2026, Liga Portugal closes the summer window. For one category of player, though, it does not close: until 8 September, clubs can still register players arriving on loan, provided they are under 23 and were trained at the club releasing them. It is written in Liga Portugal’s official communication number 1, the document that opens the season, and it is worth reading closely because it dismantles the idea that the market is a door slamming at one precise moment.
The three clocks of these days
| Clock | Deadline | What it decides |
|---|---|---|
| Portuguese national window | 23:59 on 4 September 2026 | Who can be registered in Portugal |
| Portuguese loan extension | 8 September 2026 | Loans only, of under-23 players trained at the releasing club |
| UEFA List A | 23:59 CET on 2 September 2026 | Who can play the league phase in Europe |
| Turkish national window | 4 September 2026 | Who can be registered in Turkey |
| Windows already shut | 1 September the big leagues, 2nd the Netherlands and MLS, 3rd Scotland, Belgium and Austria | Who can no longer buy |
What the league’s communication says
The document is the one that opens the season every year, official communication number 1, and it sets three dates: the summer window open until 23:59 on 4 September, the possibility of registering until 8 September players arriving on loan who are under 23 for the whole duration of the loan and were trained at the club releasing them, and the 2026-27 winter window open until 23:59 on 1 February 2027.
Then comes the sentence about what happens afterwards, and it applies across Europe: once the window is shut, only players without a contract can be registered.
On deadline day the league does something other competitions do not: it publishes running lists. The first update on 4 September came out at 14:00 and covered contracts received up to 12:30, with further lists due at 19:00 and 22:00 and the complete one after midnight. It means that in Portugal a registration can be checked against the league rather than waited for from a club statement.
Why loans of young players get four extra days
The extension is neither a favour to small clubs nor a loophole: it separates two movements that only look alike.
Buying a player means adding to your squad someone who belonged to another club, and the window exists precisely to stop squads changing shape once the season is under way. Sending out on loan a boy raised in your own academy is a different thing: the club adds nothing to itself, it places elsewhere a player who is already its own, usually because he would not find minutes in the first team.
The two conditions written into the communication make the extension hard to use as a way around the deadline. The first is about age: under 23 for the whole duration of the loan, so no mature players dressed up as youngsters. The second is the tighter one: the player must have been trained at the club releasing him, so he cannot be a signing who has just arrived and is immediately passed on.
UEFA’s clock had already run out two days earlier
This is the part most often told badly. A player registered today in Portugal or in Turkey is properly registered for his domestic league, but for European competition he arrives late: List A for the league phase had to be submitted by 23:59 CET on 2 September, with a maximum of 25 players, at least two goalkeepers and at least eight locally trained, of whom no more than four association-trained.
List B remains, and it is a narrow path rather than an alternative. It can be amended during the season, up to 23:59 CET on the day before a match, but it can only hold players born on or after 1 January 2005 who, since their 15th birthday, have been eligible to play for that club for two uninterrupted years or for three consecutive years with a maximum one-year loan.
Translated: a 20-year-old who arrived today from another club does not go on List B, because he lacks the years at the club. A boy from the academy does. That is why, in the last days of August, clubs playing in Europe chase the UEFA deadline rather than the national one: whoever signs after 2 September is a player for the league, not for the cup, at least until the January window.
What closes today elsewhere, and what stays open
4 September is also the last day of the Turkish market: the federation set the first transfer and registration period from 22 June to 4 September 2026. Before that, the five big European leagues had already closed on 1 September, the Netherlands and MLS on the 2nd, Scotland, Belgium and Austria on the 3rd.
Markets outside Europe remain open, and that leaves European clubs exposed for a few weeks yet: they can lose a player without being able to replace him, because the window that counts is the buyer’s. On the closing date of some of those markets the sources we consulted do not agree, and not having found the federation document that fixes it, we prefer not to state it as a fact.
What to watch now
Three things. The first is the complete list Liga Portugal will publish after midnight: it will be the verifiable photograph of who was registered today, without going through second-hand accounts. The second is the days up to 8 September, meaning the loans of home-grown boys: it is a small, barely covered market, but it decides where dozens of young players will spend the season. The third concerns Europe: clubs that completed deals after 2 September will play the league phase with a different squad from the one they field domestically, and the difference will show in the lists, not in the interviews.
Sources: Liga Portugal’s official communication number 1 for the summer window dates, the extension to 8 September for loans of under-23 players trained at the releasing club and the winter window deadline, as reported by the Portuguese outlets that published it; Liga Portugal for the timing of the lists published on deadline day; uefa.com for the deadlines and criteria of List A and List B in the 2026-27 league phase; the Turkish Football Federation for the dates of the first transfer period; premierleague.com for the English close on 1 September; FIFA Regulations on the Status and Transfer of Players for the registration of free agents outside the window.
Frequently asked questions
When does the Portuguese window actually close?
At 23:59 on 4 September 2026 for transfers in general, according to Liga Portugal's official communication number 1. But until 8 September it remains possible to register players arriving on loan, on two conditions: that they are under 23 for the whole duration of the loan and that they were trained at the club releasing them.
Why is there an extension only for loans of young players?
Because it covers a different movement from a signing: a club sending out a boy it raised is not strengthening its squad, it is managing the development of a player it already owns. Liga Portugal keeps four extra days open for that kind of move, while for everyone else the deadline stays 4 September.
Can a player signed today feature in the Champions League?
Not on List A, which had to be submitted by 23:59 CET on 2 September. List B remains, and it can be amended during the season up to 23:59 CET on the day before a match, but it is reserved for players born on or after 1 January 2005 who, since their 15th birthday, have been eligible to play for the club for two uninterrupted years, or for three consecutive years with a maximum one-year loan spell.
Can anyone still be registered after the deadline?
Only players without a contract. FIFA rules provide that a professional whose contract has expired before the end of a registration period may be registered outside the window, and leave associations free to fix a deadline for that case too.
Which other markets close on 4 September?
Turkey's: the Turkish federation set the first transfer and registration period from 22 June to 4 September 2026. In Europe the big leagues had already closed on 1 September, the Netherlands and MLS on the 2nd, Scotland, Belgium and Austria on the 3rd.
What does Liga Portugal publish on deadline day?
Progressive lists of the contracts received. On 4 September the first list came out at 14:00 and covered contracts received up to 12:30, with further updates due at 19:00 and 22:00 and a complete list after the close.
