This series concerns the Horowhenua County Council Rate Books for 1888 to 1958. The Rate Books are in chronological order by the rating periods. The Rate books earlier than 1888 are either missing or were lost in the fire that destroyed the Horowhenua County Council offices on the 9th February 1898. The available Rate Books that are pre 1898 show evidence of fire damage. Books are missing for the Wirokino Riding in 1892/93, Otaki Riding in 1893/94 and all ridings in 1895/96.
The Rate Books from 1888 to 1905 include all wards within each book for the county, then from 1905 to 1924 each ward has their separate Rate Book. The wards included Tokomaru, Te Horo, Wirokino and Otaki. From 1933 to 1958 all wards can then be found in the same Rate Book for each rating period. The Rate Books from 1924 to 1933 are missing and occasional books are missing for 1905-1924, these gaps are filled by the valuation rolls in series HDC 00038.