Deloitte is involved in a legal row with the City of London Corporation in a dispute over the alleged overpayment of rates.

The firm has issued a writ filed with the High Court demanding £3m from the Corporation as well as damages and interest.

Deloitte says the valuation officer altered the local lists in 1995, changing premises at Stonecutter Court from 25 separate properties to just one. The valuation officer then provided certificates stating the rateable value on an erroneous basis calculated under the Non-Domestic Rating (Chargeable Amounts) Regulations 1994, the writ says.

The discrepancy purportedly came to light when the secretary of state for transport, local government and the regions wrote to rating authorities about transitional regulations.

Chartered surveyors acting for Deloitte wrote to the Corporation last October and November requesting repayment of the overpaid rates, but the Corporation has thus far refused to pay back any money, the writ claims.

The claims relate to the period from 1995 to 2004. The City of London declined to comment.