The Mangonui Store was built on the foreshore at Mangonui in 1907 and is one a small number of trading buildings built over the water in Northland. The store has been used by a number of business owners from a variety of trades but has primarily functioned as a general store for more than 100 years. It has links to important local figures and families. The store has historic significance as one of the early stores in the Mangonui area and its close association with locally important settler families. Mangonui was an early settlement in Northland as local flax, milling and gum digging industries developed in the area during the nineteenth century and the township had formed by 1884.

In the first years of the twentieth century the main road along the coast at Mangonui was subject to reclamation and reconstruction. In 1907 Richard Theophilus Wrathall, a son of one of the early settlers in the Mangonui area, took a licence to occupy a section of the foreshore. He built the Mangonui Store on piles over the water on this foreshore section beside the wharf and leased rooms to the local dentist, fruiter, and the tailor. The Mangonui store was constructed with living spaces as well as the commercial rooms. The rectangular building was built along the road edge and had a roof extending over the pavement. Wrathall would go on to be a locally prominent figure with periods as chairman of the Mangonui County Council and of the Mangonui Hospital Board. In 1910 the local storekeeper Alexander McKay purchased the whole building and relocated his general store from across the road to his new premises.

McKay ran the store until his death in 1927 at which time he left the building and business to his wife and, after her death in 1933, their son D.J. (Chappie) McKay inherited them. Chappie added a jetty to the rear of the building for ease of making customer deliveries further afield and so customers could come to the store in their boats. The jetty was also used to bring in gum on the families gum boat. Around this time the building was expanded to double its size, extending further back over the foreshore. Chappie McKay sold the Mangonui Store in 1943 to move to Auckland.

The jetty was not in use by the mid-1960s and was removed by 1975. The ownership in the intervening time is unclear. In the early 2000s further renovations were undertaken. The living space has been rearranged with a garage added for easy access to the road. A dormer window has been added to the roof on the seaward side. And the existing deck at the rear of the extension was widened. Some interior changes have been made to the store to accommodate the business changes. The post boxes have been moved to the south east end of the building front the front. In 2017 the Store is used as a Four Square and Post shop and Kiwibank.