Mapping Forms



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 any kind of changes to the parcels, property owner must complete and submit the Splitting Parcels form or the Combining Parcels form, as applicable. 

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 and applicants can now compete and submit the DocuSign forms directly from our website. DocuSign enables property owners and applicants to securely sign and submit forms from any device.

For questions regarding Mapping forms, you may contact us or call us 650.363.4000 (extension 1227).

Submit forms using e-signature
View forms in PDF format
Splitting Parcels form is only available as a fillable PDF. Splitting Parcels
Combining Parcels Combining Parcels
Subdivision Assessment Data Request Subdivision Assessment Data Request
Request to Split Assessed Parcel for Condominiums Request to Split Assessed Parcel for Condominiums