A record £965m was spent in 2014-15, but that figure has already been beaten, with clubs having until 23:00 GMT on Monday to sign further players.
The 20 clubs have already spent £130m in the January transfer window alone, with Newcastle spending £29m which could rise to £60 million
They have signed Jonjo Shelvey, Andros Townsend and Henri Saivet, and bid £21m for West Brom striker Saido Berahino.
Dan Jones, partner in the Sports Business Group at Deloitte, reported on BBC Sport said: "We've seen Premier League clubs again use the January window to invest significantly in playing talent.
"With a day left, the total gross spending this season has already reached £1bn for the first time."
Premier League spending since 2003-04
*2015-16 January transfer window figures as at 09:00 GMT on 1 February
Year summer winter total
2003-04 £215m £50m £265m
2004-05 £215m £50m £265m
2005-06 £235m £70m £305m
2006-07 £260m £60m £320m
2007-08 £470m £175m £645m
2008-09 £500m £170m £670m
2009-10 £450m £30m £480m
2010-11 £365m £225m £590m
2011-12 £485m £60m £545m
2012-13 £490m £120m £610m
2013-14 £630m £130m £760m
2014-15 £835m £130m £965m
2015-16 £870m £130m so far £1bn so far