The Savoy Group has been served a writ for more than £2m by privately owned shopfitter and interior designer Timtec International.
The Derbyshire-based firm carried out much of the refurbishment work on Claridge's art deco and Victorian wing last year.
Both companies failed to agree a price while the refurbishment work was under way and Timtec is claiming £2.39m plus VAT.
A Savoy Group spokesman said: "We disagree with the amount asked for. Negotiations have not come to a conclusion so the company has issued a writ, which is just a procedure.
"If an agreement is reached between Claridge's and Timtec they will be paid. If not there will be litigation."