Horace joined his father as a partner in the auctioneer's business that he had started. The business was advertised in The Guildford Almanac as Messrs. Folker & Son and in 1883 was located at 64 High Street, Guildford. They advertised as Auctioneers, Valuers and Accountants, undertaking Valuations for Probate and Business Transfers. The 1884 and 1885 editions show the business as being in Guildford Chambers in North Street, and now included being Hotel Brokers and General Insurance Agents.

By 1886, Horace had moved house to 1 Khartoum Villas, Artillery Terrace in Guildford where he remained for five or six years. By then he had disolved the partnership and split from his father and traded by himself from 74 High Street, Guildford. He retained ownership of the Guildford Poultry Market which his father had started in 1876. By 1894, He had gone into partnership with Percy Horton, and the business became known as Folker & Horton, operating from 41 High Street.

The census of 1891 recorded Horace as an Auctioneer & Valuer.

The auctioneering business expanded so that by that year an office had been opened in Godalming. There are reports in The London Gazette on various dates between 1903 and 1906 detailing companies which were being wound-up and for which Horace had been appointed as liquidator.

Horace retired from the business in 1908 and the partnership was dissolved as reported in the London Gazette. His business partner retired the following year and was succeeded by two members of staff, Mr J H Gifford of Guildford who had been with the firm for seventeen years and Mr A E Furnell of Godalming who had fourteen years service. In 1910, the Folker & Horton partnership handled the auction sale of land at Slyfield Green and also around that time the sale of land near Shalford destined for the construction of the Peasemarsh Estate. The business of Folker and Horton continued until about 1959, being located until the from about 1913 at 1 The Quadrant, Bridge Street, Guildford.