Among those left out of pocket by the collapse of Middleton's family firm are multiple suppliers and the UK tax authorities, who are owed £612,685.
The family firm, where Kate Middleton worked as a website designer and photographer before her marriage to William, turned her parents into millionaires.
The company left debts of nearly £2.6 million ($3.2 million) when it collapsed last month, a report by insolvency specialists has revealed.
The unpaid bills left by the pandemic-hit firm´s collapse include over £600,000 in unpaid tax.
Party Pieces, a celebration paraphernalia mail order business, was built up by Catherine´s parents Carole and Michael Middleton.
The firm grew into a successful business and generated significant wealth for the Middletons, who in 2012 purchased a £4.7-million mansion west of London near the royal family´s Windsor estate.
According to a report, at its height, Party Pieces was said to be worth £44 million.
However, after unpaid suppliers threatened legal action earlier this year, administrators were appointed last month and the business was immediately sold to UK entrepreneur James Sinclair for an undisclosed sum.
Will Wright, of administrators Interparty Advisory, said Party Pieces had been "impacted profoundly by the effects of the pandemic and the ensuing restrictions on social gatherings."
A report from the administrators said the firm was £2.59 million short of what it needed to clear its debts.
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