While January signings begin to familiarise themselves with their new surroundings, others are having to come to terms with collapsed deals that leave them in limbo.
There are so many reasons a transfer can fall through: finances, failed medicals and a late change of mindset all among them.
With that in mind, here we take a close look at some of the proposed moves from the past month that could have gone ahead but somehow fell through.
Ivan Perisic, Yannick Carrasco and Christopher Nkunku to Arsenal
Ivan Perisic asked for a transfer from Inter Milan, and his representatives pushed ahead by trying to secure a move to Arsenal, who were very keen to conclude a deal.
The early signs were promising: Personal terms were agreed, and it was expected the Croatia international would be allowed to move on. But the matter then became more complicated.
Arsenal could not offer any cash option or a loan with an obligation to buy, which was not deemed satisfactory by those working on the deal in Italy.
The club owners brought a halt to any discussions, and Perisic was left training on his own at Inter. The Serie A side have been thinking about how to move forward until the end of the season and are now agreeing to let him resume full training with the first team.
Arsenal also failed to get Yannick Carrasco over the line, as the loan fee offered to Chinese club Dalian Yifang for the 25-year-old was deemed too low.
To sum up the Gunners' window, they also missed out on Christopher Nkunku on the last day, again due to financial issues.
This time, the problems arose when Paris Saint-Germain explained how they wanted to protect their 21-year-old, who has 18 months remaining on his contract, with a loan fee Arsenal simply could not agree to.
Marko Arnautovic to Shanghai SIPG
Marko Arnautovic's brother and agent, Danijel Arnautovic, drove the move to China, as sources indicated to B/R that he approached Shanghai SIPG with news the West Ham United frontman would be available if they made an offer of £35 million.
Clubs in England had also been made aware the 29-year-old could become available, but none went as far as making a bid.
West Ham knocked back the interest of Shanghai, as it turned out they valued him more highly. The player and his agent remained keen to push forward with the switch that would have seen his wages reach around £220,000 per week after tax, and those inside the east London club thought he would get his way.
The offer was then withdrawn by Shanghai, though, and Arnautovic bizarrely has now signed a new improved contract, which is heavily incentivised. Almost everyone around the club believes he will still move on in the summer.
Maxi Gomez to West Ham United
Even before the saga involving Arnautovic, West Ham had been searching for new talent to boost their attack in the long term.
Celta Vigo forward Maxi Gomez was the man set as No. 1 target from the first day of January, but so many clubs were interested that they never thought it would materialise.
As the month wore on, though, it became clear they did have a shot at signing the 22-year-old, and moves were made to strike a deal that would see him sign now but not join until the summer.
They were happy with his £43 million fee but they then learned the player would demand wages of £80,000 per week, which did not fit in with their current financial plans.
As such, the deal has been put on the back-burner, and the Hammers hope to pick it up again once squad players have been shifted from their wage bill.
The truth is, though, someone else probably will come along and beat them next time.
Michy Batshuayi to AS Monaco...and West Ham
After deciding to ending his loan spell with Valencia earlier in January, Michy Batshuayi initially thought he was set to link up with Thierry Henry at Monaco.
The Belgium international had been speaking directly to the then-Monaco boss about his plans for the Ligue 1 club, and he was keen to become a focal point of the side as they attempted to turn around their season.
However, the terms of the loan deal were not suitable, and the matter became more complex as Monaco appeared to backtrack.
Ultimately, however, Henry lost his job at Monaco and Batshuayi's month only got more complicated.
Chelsea were open to loan offers from both Real Betis and West Ham, but this time it was the player's wages that caused an issue. As with Gomez, the Hammers pulled back from the situation when they learned they would be directed to pay wages of around £80,000 per week as well as a £2 million loan fee.
Chelsea made a call to Crystal Palace late in the day to finally find a temporary home for the 25-year-old.
Dominic Solanke to Crystal Palace
Dominic Solanke was set to become the subject of the first significant Premier League move of the transfer window, and an agreement was so far down the line that preparations were being made to unveil him by Crystal Palace.
However, it began to become clear the 21-year-old would not be able to figure in their upcoming fixtures due to a lack of match fitness so the Eagles scrapped the deal.
Bournemouth picked up the pieces and signed him from Liverpool for £17 million, and he did not figure at all until appearing among the substitutes on Wednesday night against Chelsea.
Jordan Lukaku to Newcastle United
His brother is already a household name at Manchester United, and Newcastle were excited about the prospect of bringing Jordan Lukaku into their defence.
A new left-back was right at the top of priorities for the transfer window, and the club were confident of sealing a loan move for the Lazio player until the end of the season.
However, complications began to emerge in his medical, and it was decided they would not pursue the potential switch any further.
On deadline day, Newcastle sealed the loan signing of Monaco's Antonio Barreca instead.
Luca Murphy and Michael Ngadeu-Ngadjui to Fulham
An exciting 17-year-old defender from Hartlepool United, Luca Murphy travelled to west London and was expected to sign with Fulham.
However, the Premier League club's analytics and recruitment system appears to have played a key role in determining he could not complete a move.
Sources explained how new tests are being adopted—similar to those seen at the NFL Scouting Combine—determining that certain tasks must be carried out to a particular high standard.
It seems Murphy did not meet the requirements, and he is now expected to join another Premier League club in the summer, with Manchester United, Tottenham Hotspur and Wolverhampton Wanderers all very interested.
Fulham failed to tie up other business, too, and Slavia Prague defender Michael Ngadeu-Ngadjui will have been left disappointed after flying in on deadline day and being given the go-ahead to complete the deal by the Czech club.
The Cameroon international waited at the club for negotiations to proceed to a stage where he would put pen to paper, but officials hesitated and an agreement was never reached.