Arsenal have been sanctioned for refusing to provide Manchester United with their full allocation for the FA Cup third-round tie at the Emirates in January.
United were left frustrated after being given 8,000 tickets for the clash, 1,000 less than their entitlement under competition rules.
The Gunners had cited safety concerns as the reason for the decision, which United unsuccessfully challenged with the FA after making several complaints to the organisation in the lead-up to the match.
The seats in question were in an upper tier of Arsenal's 60,000-capacity Emirates Stadium and were left empty - despite United offering to handpick recipients, and ensure they went to families and children linked to the club's charity arm.