home home Find taxes & rates home Business & occupation tax home Apportionment under Economic Nexus Standard Apportionment under Economic Nexus Standard

Nexus Standard for Wholesale Sales - Effective Sept. 1, 2015

Nexus Standard for “Click-Through” Retail Sales - Effective Sept. 1, 2015


The economic nexus standard applies to apportionable income, which includes income derived from apportionable activities. Under the apportionment method effective June 2010 only the receipts factor for these businesses applies to apportionable income for these businesses.

Single-factor apportionment

A single-factor apportionment formula based on sales is adopted for apportionable income. Taxable income is determined by multiplying a taxpayer’s apportionable income times the receipts factor.

The receipts factor is a fraction:

  • The numerator is the total gross apportionable income attributed to Washington income during the current tax year.
  • The denominator is the total gross apportionable worldwide income during the current tax year less throwout income.


Washington income
(Worldwide income) – (Throwout income)

Throwout Income

Gross income from engaging in an apportionable activity is excluded from the denominator of the receipts factor if both:

  1. the income is attributed to a state where the taxpayer is not subject to tax or the taxpayer does not have nexus and
  2. at least some of the activity is performed in Washington.

Reconciling your apportionable income

Once a taxpayer has the information necessary to determine the receipts factor for an entire calendar year, it must file a reconciliation and either obtain a refund or pay any additional tax due. The reconciliation is due by October 31st of the following year. A reconciliation can be filed electronically through your My Account home page.

  1. Sign into My Account.
  2. On the left hand navigation bar select File a return.
  3. Click on Reconciliation of Apportionable Income.

If you are unable to complete the online form, you may complete the paper form.

Back to economic nexus and apportionment page