Prior to the merchant and guest granting commencement of the 1770s, Kjerringøy had been a church town, a town center, borgerleie, a ships dock and a place of trial for a long time. Old-age burial mounds and medieval cemetery are in the immediate vicinity.
The first who made a trade permit on Kjerringøy was Johannes S. Bernhoft in 1775. His son Adam Humbold Bernhoft runs the place after his father. The Bernhofts never manage to build the place to be particularly important.
In 1803, Christian Sverdrup buys the trading post and builds a robust business. He builds several houses, and Kjerringøy begins to gain more importance. By his death in 1829 his eldest daughter, Anna Elisabeth Ellingsen and her husband, Jens Nicolai Ellingsen, inherit the place. Ellingsen came from a family with very many traders. His father and 6 uncles deal in fish and fish products throughout Northern Nordland, and the family is strong. In 1849, Ellingsen dies, and widow Anna Elisabeth continues on her own until she marries her trade-union Erasmus BK Zahl in 1859.
Anna Elisabeth dies in 1879, Zahl in 1900. All owners of the post office after 1803 are descendants of Christen Sverdrup, but not in direct inheritance. The trading company at Kjerringøy was one of the most significant in the region during Zahl's time.