Cal. Code Regs. tit. 18, § 17951-4
(c) If a nonresident's business, trade or profession is a sole proprietorship which carries on a unitary business, trade, or profession within and without the state, the amount of net income derived from sources within this state shall be determined in the manner described below.
(d) If a nonresident is a partner in a partnership which carries on a unitary business, trade or profession within and without this state, the source of the partner's distributive share of partnership income derived from sources within this state shall be determined in the manner described below.
(6) Exception for 20 percent or more interests. Subsection (d)(5) shall not apply to partners who own, directly or indirectly, a 20 percent or more capital or profits interest in a partnership. For purposes of this section, the ownership of a capital or profits interest in a partnership shall be determined under the rules of subsection (d)(6)(B).
(B) For purposes of this subsection (d)(6), the actual or constructive ownership of a capital or profits interest in a partnership shall be determined in accordance with the following rules:
4. An interest in partnership capital or profits constructively owned by a person by reason of the application of subsection (d)(6)(B)1. shall, for the purpose of applying subsections (d)(6)(B)1. or (d)(6)(B)2., be treated as actually owned by such person, but an interest in partnership capital or profits constructively owned by an individual by reason of the application of subsection (d)(6)(B)2. shall not be treated as owned by him for the purpose of again applying either of such subsections in order to make another the constructive owner of such interest in partnership capital or profits.
Example: Individual X is engaged in a sole proprietorship with business income of $100,000. In addition, X directly owns a 15% capital interest in Partnership P. X's sister Y also owns a 10% capital interest in P. X's distributive share of business income from P is $30,000, and his sister's distributive share of business income from P is $20,000. P and X's sole proprietorship are engaged in a unitary business. Under subsection (d)(6)(B), X is treated as constructively owning Y's interest in the partnership. Thus X's aggregate owned or constructively owned interest in P is 25%. Accordingly, X is subject to the apportionment provisions of subsection (d)(6)(A). However, under subsection (d)(6)(A), X will combine and apportion only the sum of his $100,000 proprietorship income and his actual distributive share of business income of $30,000 from P. The 20 percent test used to determine the applicability of subsection (d)(6) does not affect the amount of partnership income taken into account in computing income actually derived from sources within this state.
(g) For taxable years beginning on or after January 1, 2013, all business income is subject to the single sales factor apportionment formula pursuant to Section 25128.7, Revenue and Taxation Code, unless subdivision (b) of Section 25128, Revenue and Taxation Code, applies. If a sole proprietorship or partnership described in subsections (c) or (d) is engaged in the practice of a profession within the meaning of subsection (h), below, the payroll factor, where applicable, of the applicable apportionment formula shall include 60% of the net income of a sole proprietorship or 60% of the distributive share of partnership income of each partner rendering professional personal services to the partnership. For purposes of the payroll factor the net income of a sole proprietorship and a partner's distributive share of partnership income shall consist only of income properly classifiable as business income. The amount so determined is deemed to be compensation paid to an employee for purposes of the payroll factor only. If a partner does not render professional services to the partnership, no part of such partner's distributive share of partnership income shall be taken into account in the payroll factor. The amount deemed to be compensation paid to an employee shall be included in the denominator of the payroll factor and in the California numerator of the payroll factor if the principal location of such partner is in this state.
Guaranteed payments to a partner who renders professional services to a partnership engaged in the practice of a profession (within the meaning of subsection (h) below) shall be treated as part of the partner's distributive share of partnership income and has a source in this state in the same manner as a distributive share properly classified as business income and shall be apportioned under subsection (d), as modified under subsection (g). In computing the payroll factor of a partner who renders professional services to such a partnership and receives a guaranteed payment, 60 percent of the sum of the partner's distributive share of partnership income properly classified as business income, and the partner's guaranteed payment, shall be deemed to be compensation paid to an employee. The amount deemed to be compensation shall be included in the denominator of the payroll factor and in the California numerator of the payroll factor if the principal location of such partner is in this state.
Example: The A-B-C company is a partnership performing accounting services within and without this state. There are three partners, A, B, and C. Partners A and B render professional services to the partnership. Partner C is not active in the partnership business. Partner A is a resident of this state, and Partners B and C are nonresidents. For purposes of this example, each partner's principal location is in his or her respective state of residence. The partners' distributive shares of profit or loss are: A, 50%; B, 30%; and C, 20%. In addition, Partner B receives a guaranteed payment of $10,000. Partnership profits after the deduction for the guaranteed payment are $60,000 for the year. Of that amount, $50,000 is business income and $10,000 is nonbusiness income from a California real estate rental. All of the nonbusiness income is sourced to this state for purposes of this example. The partnership's income apportionment percentage for this state is determined as follows:
Everywhere
This State
%
Property
$200,000
$70,000
35
Sales
150,000
64,500
43
Sales
150,000
64,500
43
Payroll:
Employees
56,000
21,000
Partners:
A--$50,000 x 50% x 60%
15,000
15,000
B--[($50,000 x 30%) + $10,000] X 60%
$15,000
-0-
Total Payroll
$86,000
$36,000
41.86
162.86
Apportionment percentage (162.86 / 4)
40.72%
The partnership's business income from sources within this state is:
Business income ($50,000 x 40.72%)
$20,360
Partner A
As a resident, Partner A is taxed on that partner's entire distributive share of ABC's income, irrespective of the source of the income:
A's share of partnership business income ($50,000) x 50%
$25,000
A's share of partnership nonbusiness rental income ($10,000 x 50%)
-
$ 5,000
A's income taxed by this state
$30,000
As nonresidents, Partners B and C are taxed on their distributive share of partnership income from sources within this state, determined as follows:
Partner B
Partner B's share of Partnership business income from sources within this state ($20,360 x 30%)
$6,108
Partner B's guaranteed payment $10,000 x 40.72%
$4,072
Partner B's share of nonbusiness rental income ($10,000 x 30%)
$3,000
Partner B's Income from sources within this state
$13,180
Partner C
Partner C's share of Partnership business income from sources within this state ($20,360 x 20%)
$4,072
Partner C's share of nonbusiness rental income ($10,000 x 20%)
$2,000
Partner C's Income from sources in this state
$6,072
(i) Rules and Definitions. To give effect to the foregoing, the following rules and definitions will be applied:
(3) Gross Income Derived From Personal Services of an Individual or Partner. For purposes of determining whether more than 80% of the unincorporated business gross income is derived from personal services actually rendered by an individual or partner, gross income from the professional practice will be deemed derived from the personal services rendered by an individual or partner if such income is personal service income as distinguished from income attributable to the sale of property or to the use of capital and such income represents fees or charges for professional services personally rendered by the individual or partner or professional fees or charges for services which are attributable to the professional activities of the individual or partner. In cases where an individual or partner employs assistants to perform part of the professional work, fees or charges relating to the services of he assistants will be attributed to the individual or partner provided the individual or partner (A) gives personal attention to the work of the business, (B) consults with clients or patients, (C) devises the work program, outlines work methods and guides and directs the work procedure of the employees in the activity, and (D) supervises the formulation of advice, conclusions and reports to clients or patients as the person responsible for the services performed by the business or establishment; or provided that some combination of the foregoing and/or other activities shows that the services of the employees are merely incidental to the practice of the profession by the individual or partner. Where the profession is carried on by a sole proprietorship or partnership, income or fees relating to work performed by employees will be attributable to an individual or partner only if, in addition to the conditions enumerated above with respect to individuals or partners, it is shown that the clients or patients are advised by an individual or partner and look to an individual or partner as being responsible for the services performed.
For example, where an accounting partnership employs assistants to do much of the detail work of making surveys, studies, audits, or other work ordinarily and customarily performed as an incident to the practice of the profession involved, income from professional charges based on services of the assistants will be deemed to be income derived from the services of the partners if a partner accepts the engagement or employment, supervises and directs the work, confers with clients, and prepares and edits or completes and approves the reports. Where the nature and character of the service rendered by the assistants is such that the services are rendered without any substantial control by a partner, such services will not be considered attributable to the partner for the purposes of this subsection.
(j) This regulation shall apply to taxable years beginning on or after January 1, 1976, except that the amendments to subsections (c)(3), (d)(4), (e) and (f), to the extent that these subsections adopt the sourcing rules of Sections 17951 through 17955, Revenue and Taxation Code, and the regulations thereunder, and not the nonbusiness allocation rules of the Uniform Division of Income for Tax Purposes Act, Sections 25120 to 25139, inclusive, Revenue and Taxation Code, and the regulations thereunder, shall apply to the computation of taxes for taxable years of sole proprietors, partners, members and shareholders beginning on or after January 1, 2001, and the amendments to subsections (d)(5), (d)(6), (e) and (f), to the extent that the business activity of a partnership, limited liability company or S corporation will not ordinarily be considered part of a unitary business activity with another business activity unless the partner, member or shareholder owns directly or indirectly a 20 percent or more capital or profits interest in a partnership, limited liability company or S corporation, or the Franchise Tax Board determines that such combination is appropriate after conducting a comparable uncontrolled price examination, shall apply to the computation of taxes for taxable years of sole proprietors, partners, members and shareholders beginning on or after January 1, 2001. In the case of the computation of additions to tax under Section 18682, Revenue and Taxation Code, for failure to pay estimated tax, and the assessment of withholding liability and penalties under Sections 18815, 18684.2, 18685, and 19409, Revenue and Taxation Code, the amendments to subsections (c)(3), (d)(4), (d)(5), (d)(6), (e) and (f) which apply to taxable years beginning on or after January 1, 2001, shall also apply for taxable years of sole proprietors, partners, members and shareholders beginning on or after January 1, 2001. The remaining amendments to subsection (d) are applicable only as of the effective date of the amendments to this subsection of the regulation.
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*** This regulation is substantially the same as Title 18, Cal. Adm. Code, Chapter 3, Subchapter 2, Section 17211-14(c).
Note: Authority cited: Sections 17954 and 19503, Revenue and Taxation Code. Reference: Sections 17041, 17854, 17951 and 25128, Revenue and Taxation Code.
1. Repealer and new section filed 7-9-76; effective thirtieth day thereafter (Register 76, No. 28).
2. Renumbering and amendment of sections 17951-17954(d) to section 17951-4 filed 1-15-82; effective thirtieth day thereafter (Register 82, No. 3).
3. Amendment of subsections (c), (d) and (i) and Note filed 3-18-94; operative 4-18-94 (Register 94, No. 11).
4. Amendment filed 12-24-2001; operative 1-23-2002 (Register 2001, No. 52).
5. Change without regulatory effect amending subsections (d)(5)(A) and (g) filed 12-9-2013 pursuant to section 100, title 1, California Code of Regulations (Register 2013, No. 50).
6. Amendment of subsection (d)(1), new subsection (d)(2), subsection renumbering and amendment of newly designated subsections (d)(5)-(d)(6)(B) and (d)(6)(B)4. and subsections (f) and (j) filed 11-20-2018; operative 1-1-2019 (Register 2018, No. 47).