Last summer saw some huge transfers completed with Manchester City signing Jack Grealish for £100million, Man United bringing Cristiano Ronaldo back to Old Trafford and Chelsea spending £97m on Romelu Lukaku.
January is always a tough month to get business done but teams around the country may be forced to splash out ahead of the second half of the campaign.
With the window now open, here's all the confirmed ins and outs across the top-flight so far…
Arsenal
In
Out
Aston Villa
In
Out
Keinan Davis [Nottingham Forest] Loan
Brentford
In
Jonas Lossl [Midtjylland] Loan
Out
Brighton & Hove Albion
In
Out
Aaron Connolly [Middlesbrough] Loan
Burnley
In
Out
Chelsea
In
Out
Crystal Palace
In
Out
Everton
In
Vitaliy Mykolenko [Dynamo Kyiv] Undisclosed
Out
Leeds United
In
Out
Leicester
In
Out
Liverpool
In
Out
Manchester City
In
Out
Ferran Torres [Barcelona] - £50m
Manchester United
In
Out
Newcastle United
In
Out
Norwich
In
Out
Southampton
In
Out
Tottenham Hotspur
In
Out
Watford
In
Maduka Okoye [Sparta Rotterdam] Undisclosed
Nicolas Nkoulou - Unattached
Out
West Ham United
In
Out
Wolves
In
Out
Fiorentina 
Udinese 
Benfica 
Estoril 
Inter 
Como 
Manchester City 
Everton 
Chelsea 
Fulham 
Nottingham Forest 
Tottenham 
Celtic 
Motherwell 
Wolverhampton 
Manchester Utd 
ST Mirren 
Rangers 
Sampdoria 
Carrarese 
Liverpool 
Leicester 
Arsenal 
Ipswich 
Cagliari 
Lazio 
Atalanta 
FC Porto 
Boavista 
Torino 
Napoli 
Venezia 
ST Johnstone 
Juventus 
West Ham 
Pisa 
AC Milan 
Roma 
Sporting CP 
Newcastle 
Brentford