The Hammers can move up to third in the Premier League table with a win over Newcastle this weekend after beating Leicester City on Sunday and will then have just six games remaining to seal European qualification. Fourth place is enough to ensure entering the group stages of the European competition.
Mark Noble negotiated the Champions League bonus with the West Ham board ahead of the season, having also led talks over wage deferrals during the first lockdown last year.
There is no additional bonus for a Europa League qualification, but there is an incremental bonus system in place which starts with a ninth-place finish.
West Ham will also need to pay out a £500,000 bonus to Manchester United as part of the Jesse Lingard loan deal if the Hammers achieve any European qualification.
Champions League would earn the Hammers tens of millions in extra revenue so a £9m bonus pool would be the least of their concerns this summer.