(a) This section applies to persons entitled to apportion income under RCW 82.04.460(1). Specifically this section applies to taxpayers who maintain places of business both within and without the state that contribute to the rendition of services and who are taxable under RCW 82.04.290, 82.04.2908, or any other statute that provides for apportionment under RCW 82.04.460(1). Persons subject to the service and other activities, international investment income, licensed boarding home, and low-level radioactive waste disposal business and occupation (B&O) tax classifications, and who are not required to apportion their income under another statute or rule, should use this section. In addition, this section describes Washington nexus standards for business activities subject to apportionment under RCW 82.04.460(1). Nexus is described in subsection (2) of this section; separate accounting in subsection (3) of this section; and cost apportionment in subsection (4) of this section.

     (b) Readers may also find helpful information in the following rules:

     (i) WAC 458-20-14601 (Financial institutions -- Income apportionment).

     (ii) WAC 458-20-170 (Constructing and repairing of new or existing buildings or other structures upon real property).

     (iii) WAC 458-20-179 (Public utility tax).

     (iv) WAC 458-20-193 (Inbound and outbound interstate sales of tangible personal property).

     (v) WAC 458-20-236 (Baseball clubs and other sport organizations).

     (c) The examples included in this section identify a number of facts and then state a conclusion. These examples should be used only as a general guide. The tax results of all situations must be determined after a review of all the facts and circumstances.

     (2) Nexus.

     (a) Place of business - minimum presence necessary for tax. The following discussion of nexus applies only to gross income from activities subject to apportionment under this rule. A place of business exists in a state when a taxpayer engages in activities in the state that are sufficient to create nexus. Nexus is that minimum level of business activity or connection with the state of Washington which subjects the business to the taxing jurisdiction of this state. Nexus is created when a taxpayer is engaged in activities in the state, either directly or through a representative, for the purpose of performing a business activity. It is not necessary that a taxpayer have a permanent place of business within a state to create nexus.

     (b) Examples. The following examples demonstrate Washington's nexus principles.

     (i) Assume an attorney licensed to practice only in Washington performs services for clients located in both Washington and Florida. All of the services are performed within Washington. The attorney does not have nexus with any state other than Washington.

     (ii) Assume the same facts as the example in (b)(i) of this subsection, plus the attorney attends continuing education classes in Florida related to the subject matter for which his Florida clients hired him. The attorney's presence in Florida for the continuing education classes does not create nexus because he is not engaging in business in Florida.

     (iii) Assume the same facts as the example in (b)(ii) of this subsection, plus the attorney is licensed to practice law in Florida and frequently travels to Florida for the purpose of conducting discovery and trial work. Even though the attorney does not maintain an office in Florida, the attorney has nexus with both Washington and Florida.

     (iv) Assume an architectural firm maintains physical offices in both Washington and Idaho. The architectural firm has nexus with both Washington and Idaho.

     (v) Assume an architectural firm maintains its only physical office in Washington, and when the firm needs a presence in Idaho, it contracts with nonemployee architects in Idaho instead of maintaining a physical office in Idaho. Employees of the Washington firm do not travel to Idaho. Instead, the contract architects interact directly with the clients in Idaho, and perform the services the firm contracted to perform in Idaho. The architectural firm has nexus with both Washington and Idaho.

     (vi) Assume the same facts as the example in (b)(v) of this subsection except the contracted architects never meet with the firm's clients and instead forward all work products to the firm's Washington office, which then submits that work product to the client. In this case, the architectural firm does not have nexus with Idaho. The mere purchase of services from a subcontractor located in another state that does not act as the business' representative to customers does not create nexus.

     (vii) Assume that an accounting firm maintains its only office in Washington. The accounting firm enters into contracts with individual accountants to perform services for the firm in Oregon and Idaho. The contracted accountants represent the firm when they perform services for the firm's clients. The firm has nexus with Washington, Oregon, and Idaho.

     (viii) Assume that an accounting firm maintains its only office in Washington and has clients located in Washington, Oregon, and Idaho. The accounting firm's employees frequently travel to Oregon to meet with clients, review client's records, and present their findings, but do not travel to Idaho. The accounting firm has nexus with Washington and Oregon, but does not have nexus with Idaho.

     (ix) Assume that a sales representative earns commissions from the sale of tangible personal property. The sales representative is located in Oregon and does not enter Washington for any business purpose. The sales representative contacts Washington customers only by telephone and earns commissions on sales of tangible personal property to Washington customers. The sales representative does not have nexus with Washington and the commissions earned on sales to Washington customers are not subject to Washington's business and occupation tax.

     (x) The examples in this subsection (2) apply equally to situations where the Washington activities and out-of-state activities are reversed. For example, in example (b)(ix) of this subsection, if the locations were reversed, the sales representative would have nexus with Washington, but not in Oregon.

     (3) Separate accounting.

     (a) In general. "Separate accounting" refers to a method of accounting that segregates and identifies sources or activities which account for the generation of income within the state of Washington. Separate accounting is distinct from cost apportionment, which assigns a formulary portion of total worldwide income to Washington. A separate accounting method must be used by a business entitled to apportion its income under RCW 82.04.460(1) if this use results in an accurate description of gross income attributable to its Washington activities.

     (b) Accuracy. Separate accounting is accurate only when the activities that significantly contribute, directly or indirectly, to the production of income can be identified and segregated geographically. Separate accounting thus links taxable income to activities occurring in a discrete jurisdiction. The result is inaccurate when services directly supporting these activities occur in different jurisdictions. For example, if a taxpayer provides investment advice to clients in Washington, but performs all of its research and due diligence activities in another state, then separate accounting would not be accurate. However, if instead of research and due diligence, only the client billing activity is performed in another state, then separate accounting would be allowed.

     (c) Approved methods of separate accounting. The following methods of separate accounting are acceptable to the department, if accurate:

     (i) Billable hours of employees or representative third parties performing services in Washington. If a business charges clients an hourly rate for the performance of services, and the place of performance of the employee, contractor, or other individual whose time is billed is reasonably ascertainable, then the billable hours may be used as a basis for separate accounting. The gross amount received from hours billed for services performed in Washington should be reported.

     (ii) Specific projects or contracts. A business may assign the revenue from specific projects or contracts in or out of Washington by the primary place of performance. For example:

     (A) A consulting business with no other presence in Washington that agrees to provide on-site management consulting services for a Washington business and receives five hundred thousand dollars in payment for the project must report five hundred thousand dollars in gross income to Washington.

     (B) If the same business gets another Washington client for on-site management consulting, and receives another payment of five hundred thousand dollars, the business must report an additional five hundred thousand dollars in gross income to Washington.

     (C) If a business contracts to distribute advertisements for another business within the state of Washington, the gross amount received for this action should be reported as Washington income.

     (iii) Other reasonable and accurate methods -- Notice to the department.

     (A) A taxpayer may report with, or the department may require, the use of one of the alternative methods of separate accounting.

     (B) A taxpayer reporting under this subsection must notify the department at the time of filing that it is using an alternative method and provide a brief description of the method employed. If a taxpayer reports using an alternate method, the same method must be used for all subsequent tax reporting periods unless it is demonstrated another method is necessary under the standard in (c)(iii)(E) of this subsection.

     (C) If on review of a taxpayer's return(s) the department determines another method is necessary to fairly represent the extent of a taxpayer's business activity in Washington, then the department may impose the method for all returns within the statute of limitations. Statutory interest applies to both balances due and refund or credit claims arising under this section. Further, applicable penalties will be imposed on balances due arising under this section. However, if the taxpayer reported using the separate accounting method in (c)(i) or (ii) of this subsection or cost apportionment under subsection (4)(a) through (h) of this section, the department may impose the alternate method for future periods only.

     (D) A taxpayer may request that the department approve an alternative method of separate accounting by submitting a request for prior ruling pursuant to WAC 458-20-100. Such letter ruling may be subject to audit verification before issuance.

     (E) The taxpayer or the department, in requesting or imposing an alternate method of separate accounting, must demonstrate by clear and convincing evidence that the separate accounting methods in (c) of this subsection do not fairly represent the extent of the taxpayer's business activity in Washington.

     (4) Cost apportionment.

     (a) Apportionment ratio.

     (i) Each cost must be computed according to the method of accounting (cash or accrual basis) used by the taxpayer for Washington state tax purposes for the taxable period. Persons should refer to WAC 458-20-197 (When tax liability arises) and WAC 458-20-199 (Accounting methods) for further guidance on the requirements of each accounting method. Taxpayers must file returns using costs calculated based on the taxpayer's most recent fiscal year for which information is available, unless there is a significant change in business operations during the current period. A significant change in business operations includes commencement, expansion, or termination of business activities in or out of Washington, formation of a new business entity, merger, consolidation, creation of a subsidiary, or similar change. If there is a significant change in business operations, then the taxpayer must estimate its cost apportionment formula based on the best records available and then make the appropriate adjustments when the final data is available.

     (ii) The apportionment ratio is the cost of doing business in Washington divided by the total cost of doing business as described in RCW 82.04.460(1). The apportionment ratio is calculated under this section as follows. The denominator of the apportionment ratio is the worldwide costs of the apportionable activity and the numerator is all costs specifically assigned to Washington plus all costs assigned to Washington by formula, as described below. Costs are calculated on a worldwide basis for the tax reporting period in question. The tax due to Washington is calculated by multiplying total income times the apportionment ratio times the tax rate. Available tax credits may be applied against the result. Statutory interest and penalties apply to underreported income. For the purposes of this rule, "total income" means gross income under the tax classification in question, less deductions, calculated as if the B&O tax classification applied on a worldwide basis.

     (b) Place of business requirement. A taxpayer must maintain places of business within and without Washington that contribute to the rendition of its services in order to apportion its income. This "place of business" requirement, however, does not mean that the taxpayer must maintain a physical location as a place of business in another taxing jurisdiction in order to apportion its income. If a taxpayer has activities in a jurisdiction sufficient to create nexus under Washington standards, then the taxpayer is deemed to have a "place of business" in that jurisdiction for apportionment purposes. See subsection (2) of this section.

     (c) Noncost expenditures. The following is a list of expenditures that are not costs of doing business within the meaning of RCW 82.04.460 and are therefore excluded from both the numerator and the denominator of the apportionment ratio. Expenditures that are not costs of doing business include expenditures that exchange one business asset for another; that reflect a revaluation of an asset not consumed in the course of business; or federal, state, or local taxes measured by gross or net business income. This list is not exclusive. Costs of an activity taxable under another BO tax classification are also excluded from the apportionment ratio. Similarly, the costs of acquiring a business by merger or otherwise, including the financing costs, are not the costs of doing the apportioned business activity and must be excluded from the cost apportionment calculation.

     (i) The cost of acquiring assets that are not depreciated, amortized, or otherwise expensed on the taxpayer's books and records on the basis of generally accepted accounting principles (GAAP), or a loss incurred on the sale of such assets. For example, expenditures for land and investments are excluded from the cost apportionment formula.

     (ii) Taxes (other then taxes specifically related to items of property such as retail sales or use taxes and real and personal property taxes).

     (iii) Asset revaluations such as stock impairment or goodwill impairment.

     (iv) Costs of doing a business activity subject to the B&O tax under a classification other than RCW 82.04.290 or 82.04.2908. For example, if a taxpayer were subject to manufacturing, wholesaling and service and other activities B&O tax, the costs associated with a warehouse and a manufacturing plant (property and employee costs) are excluded from the cost apportionment formula. But if costs support both the service activity and either manufacturing or wholesaling (for example, costs associated with headquarters or joint operating centers), then those costs must be included in the cost apportionment formula without segregating the service portion of the costs.

     (d) Specifically assigned costs. Real or tangible personal property costs, employee costs, and certain payments to third parties are specifically assigned under (e) through (g) of this subsection.

     (e) Property costs.

     (i) Definitions. Real or tangible personal property costs are defined to include:

     (A) Depreciation as reported on the taxpayer's books and records according to GAAP, provided that if a taxpayer does not maintain its books and records in accordance with GAAP, it may use tax reporting depreciation. A taxpayer may not change its method of calculating depreciation costs without approval of the department;

     (B) Maintenance and warranty costs for specific property;

     (C) Insurance costs for specific property;

     (D) Utility costs for specific property;

     (E) Lease or rental payments for specific property;

     (F) Interest costs for specific property; and

     (G) Taxes for specific property.

     (ii) Assignment of costs. Real or tangible personal property costs are assigned to the location of the property. Property in transit between locations of the taxpayer to which it belongs is assigned to the destination state. Property in transit between a buyer and seller and included by a taxpayer in the denominator of the apportionment ratio in accordance with its regular accounting practices is assigned to the destination state. Mobile or movable property located both within and without Washington during the measuring period is assigned in proportion to the total time within Washington during the measuring period. An automobile assigned to a traveling employee is assigned to the state to which the employee's compensation is assigned below or to the state in which the automobile is licensed. Where a business contracts for the maintenance, warranty services, or insurance of multiple properties, the relative rental or depreciation expense may be used to assign these costs.

     (f) Employee costs.

     (i) Definitions. For the purposes of this subsection:

     (A) "Compensation" means wages, salaries, commissions, and any other form of remuneration paid to or accrued to employees for personal services. Employer contributions under a qualified cash plan, deferred arrangement plan, and nonqualified deferred compensation plan are considered compensation. Stock based compensation is considered compensation under this rule to the extent included in gross income for federal income tax purposes.

     (B) "Employee" means any individual who, under the usual common-law rules applicable in determining the employer-employee relationship, has the status of an employee, but does not include corporate officers.

     (ii) Allocation method. Employee costs include all compensation paid to employees and all employment based taxes and other fees, for example, amounts paid related to unemployment compensation, labor and industries insurance premiums, and the employer's share of Social Security and Medicare taxes. An employee's compensation is assigned to Washington if the taxpayer reports the employee's wages to Washington for unemployment compensation purposes. Employee wages reported for federal income tax purposes may be used to assign the remaining compensation costs.

     (g) Representative third-party costs.

     (i) Definitions. For the purposes of this section:

     "Representative third party" includes an agent, independent contractor, or other representative of the taxpayer who provides services on behalf of the taxpayer directly to customers. The term includes leased employees who meet the standards under (g) of this subsection.

     (ii) Allocation method. Payments to a representative third party are assigned to the third party's place of performance. For example, if a business subcontracts with a representative third party who provides services on behalf of the taxpayer from a California location, the cost of compensating the representative third party is assigned to California. This is true even if the third party provides services to Washington customers. Conversely, the cost of compensating a representative third party providing services to California customers from a Washington location is assigned to Washington.

     (iii) Examples.

     (A) X, a Washington business, hires Taxpayer to design and write custom software for a document management system. Taxpayer subcontracts with Z, whose employees determine the needs of X, negotiate a statement of work, write the custom software, and install the software. Z's employees perform all of these services on-site at the X business location. Taxpayer's payments to Z are representative third-party costs and specifically assigned to Washington.

     (B) Taxpayer, a service provider, subcontracts with X, who agrees to maintain a customer service center where staff will answer telephone inquiries about Taxpayer's services. X in turn subcontracts with Z, whose employees actually respond to questions from a phone center located in California. The payments by taxpayer to X are representative third-party costs with respect to Taxpayer because X is responsible for providing the staff of the service center. The payments to X are specifically assigned to California.

     (C) Taxpayer sells various manufacturers' products at wholesale on a commission basis. Taxpayer subcontracts with X, who agrees to act as Taxpayer's sales representative on the West Coast. Taxpayer has various other sales representatives working on as independent contractors, who are assigned territories, but may make sales from an office or through in-person visits, or a combination of both. Taxpayer does not maintain records sufficient to show the representatives' places of performance. Taxpayer may use sales records and the standards under (h) of this subsection to assign commissions by each subcontractor.

     (h) Costs assigned by formula.

     (i) Costs not specifically assigned under (e) through (g) of this subsection and not excluded from consideration by (c) of this subsection are assigned to Washington by formula. These costs are multiplied by the ratio of sales in Washington over sales everywhere. For example, if a business has one thousand dollars in other unassigned costs and sales of ten thousand dollars in each of the four states in which it has nexus under Washington standards (including Washington), twenty-five percent ($10,000/$40,000), or two hundred fifty dollars of the other costs are assigned to Washington.

     (ii) Sales are assigned to where the customer receives the benefit of the service. If the location where the services are received is not readily determinable, the services are attributed to the location of the office of the customer from which the services were ordered in the regular course of the customer's trade or business. If the ordering office cannot be determined, the services are attributed to the office of the customer to which the services are billed.

     (iii) If under the method described above a sale is attributed to a location where the taxpayer does not have nexus under Washington standards, the sale must be excluded from both the numerator and denominator of the sales ratio. For the purposes of this calculation only, the department will presume a taxpayer has nexus anywhere the taxpayer has employees or real property, or where the taxpayer reports business and occupation, franchise, value added, income or other business activity taxes in the state. The burden is on the taxpayer to demonstrate nexus exists in other states.

     (i) Alternative methods.

     (i) A taxpayer may report with, or the department may require, the use of one of the alternative methods of cost apportionment described below:

     (A) The exclusion of one or more categories of costs from consideration;

     (B) The specific allocation of one or more categories of costs which will fairly represent the taxpayer's business activity in Washington; or

     (C) The employment of another method of cost apportionment that will effectuate an equitable apportionment of the taxpayer's gross income.

     (ii) A taxpayer reporting under (i) of this subsection must notify the department at the time of filing that it is using an alternative method and provide a brief description of the method employed. If a taxpayer reports using an alternate method, the same method must be used for all subsequent tax reporting periods unless it is demonstrated another method is necessary under the standard in (i)(v) of this subsection.

     (iii) If on review of a taxpayer's return(s) the department determines another method is necessary to fairly represent the extent of a taxpayer's business activity in Washington, the department may impose the method for all returns within the statute of limitations. Statutory interest applies to both balances due and refund or credit claims arising under this section. Further, applicable penalties will be imposed on balances due arising under this section. However, if the taxpayer reported using the cost apportionment method in (a) through (h) of this subsection and separate accounting is unavailable, the department may impose the alternate method for future periods only.

     (iv) A taxpayer may request that the department approve an alternative method of cost apportionment by submitting a request for prior ruling pursuant to WAC 458-20-100. Such letter ruling may be subject to audit verification before issuance.

     (v) The taxpayer or the department, in requesting or imposing an alternate method, must demonstrate by clear and convincing evidence that the cost apportionment method in (a) through (h) of this subsection does not fairly represent the extent of the taxpayer's business activity in Washington.