After his death in 1846 his widow, Elizabeth, took over the business and in 1847 extended it to include the running of omnibuses, operating a service between Pimlico and Mansion House.
Four years later the two sons parted company and ran separate businesses, John Manley operating buses and mail vans (having obtained a substantial contract with the Post Office), and William Samuel operating buses and cabs.
As a result of fierce competition by motor buses, horse bus operation ceased in 1912.
In 1919 Birch commenced operating coaches on "See Britain" tours and in 1925 re-entered the London omnibus business.
The coach hire business was retained until 1971, when it was sold to George Ewer Ltd., and Birch Brothers closed down.