The firm was founded in Towcester in Northamptonshire in 1790 by Richard Howes and continued to expand within the county throughout the nineteenth century.

Although the Percival name did not feature in the name of the firm for the first century or so, it was Richard's marriage to Mary Percival that brought the two families together. Successive members of the family remained partners in the firm until 2005 when Michael Percival, the seventh generation of his family to be a partner, retired from the partnership.

The modern commercial law firm of Howes Percival can trace its origins back to a period of rapid growth during the 1980s. That expansion saw the number of offices increase, including Milton Keynes and Norwich. During the 1990s the firm opened an office in Leicester and in 2008 opened an office in Manchester. In 2015 the Milton Keynes office moved into new premises at Knowlhill, Milton Keynes and the new Cambridge office opened.