Splitting or Combining Parcels



Any San Mateo County property owner can request that their parcel be split or combined with other parcels that they own if an APN can be described/delineated by existing parcel and/or lot lines and the parcels of land in the opinion of the assessor can be redefined without compromising ownership, tax rate areas, general use and assessment of the land.

To make this kind of change, an owner must put their request in writing, meet the legal requirements (specified on the form) and mail or hand-deliver the signed request to our office. (The law doesn’t permit the acceptance of electronic signatures at this time, so online submittal is not permitted).

What is an assessment parcel? An “assessment parcel” is a land area that is under one ownership and for general use. Parcels are referred to by their “assessment parcel number”or APN. An APN delineates land area as it is owned rather than as it may have been plotted on a subdivision or other map. It is an area of land that in the opinion of the assessor should be included under one description for assessment purposes after consideration of all legal factors.(Assessor Handbook 215)

Property owners can now download these forms directly from our website.

Splitting Parcels
Combining Parcels
Subdivision Assessment Data Request
Request to Split Assessed Parcel for Condominiums

For more information:

Send us a message

Drop-off or mail requests to:

San Mateo County Assessor Division
555 County Center, 3rd Floor – ATTN: Mapping
Redwood City, CA 94063