California Mandatory Single Sales Factor Apportionment for Most

California votes cast their ballots in favor or mandatory single sales factor apportioment for most multistate taxpayers. Propostion 39 requires most mulistate taxpayers to use a sales factor-only apportionment formula, combined with market-based sales sourcing for sales other than sales of tangible personal property. The new law is effective for tax years beginning on or after January 1, 2013. California's rules regarding market-based sorucing of sales of other than tangible personal property had previously been applicable only to taxpayers electing to apportion on a sales factor-only basis. The recent change in California's laws to single sales factor apportionment combined with market based sales sourcing for sales other than sales of tangible personal property may have an significant impact on the amount of tax that your company or your client's pay to the State of California.