The Blues signed Lukaku for around £95m, with reports claiming that Chelsea planned to pay the amount in instalments over 12 months.
Thomas Tuchel's side refused to reveal details of the deal, but Inter made the documents public when they needed to refinance their debts last year.
The documents revealed that the Serie A giants have not received the full transfer fee yet, but they are not expected to receive the money only from Chelsea.
Tuchel's side paid the initial instalment, but then Inter arranged to receive more money from an unnamed financial institution. They received £18.4m by September 2021, with almost £71m left to be paid out.
Roman Abramovich still technically owns Chelsea despite having his assets frozen by the UK Government, and whoever ends up purchasing the club, will end up inheriting a business that requires £365.3m of extra funding from him over the last five years.
Chelsea also stand to lose an estimated £600,000 per game as sanctions placed on Abramovich will prevent the club from selling tickets for games at Stamford Bridge.
The Blues are set to host Brentford, West Ham, Wolves, and Watford in the Premier League, and could also host home ties in the FA Cup and Champions League - which could total a loss of at least £2.4million.
Other sanctions imposed on Chelsea include not being able to sell merchandise, renew contracts, or sign new players.