Contra Costa County sales tax details The minimum combined 2025 sales tax rate for Contra Costa County, California is 8.75%. This is the total of state, county, and city sales tax rates. The California sales tax rate is currently 6.0%. The Contra Costa County sales tax rate is 0.25%.
If you are: a person (this includes sole-proprietors) you may claim up to $12,500; if you are a Corporation, limited liability company or partnership, you may claim up to $6,250.