The rule is one-directional, and knowing that immediately narrows who should worry. New York's guidance is explicit: days worked at home "are considered New York work days only if the employee's assigned or primary work location is at an established office or other bona fide place of business of the employer ... in New York State. If the employee's assigned or primary work location is at an established office or other bona fide place of business of the employer outside New York State, then any normal work day worked at home would be treated as a day worked outside New York State." A fully remote employee with no assigned office in the state is in a different position from one whose desk is in Manhattan.
The escape has a published score, and that score is the most useful thing on this page. For tax years beginning on or after January 1, 2006, a normal work day at a home office is treated as a day worked outside New York if the home office is a bona fide employer office. To qualify, the office "must meet either: a) the primary factor, or b) at least 4 of the secondary factors and 3 of the other factors." There are six secondary factors and ten other factors, so the arithmetic of the second route is four out of six plus three out of ten.
The primary factor is written to be hard to satisfy. It reads: "The home office contains or is near specialized facilities." The guidance's own illustration is an employee whose duties require a test track to test new cars, where no test track is available at the employer's New York offices but one is near the employee's home. It then supplies the counter-example: equipment set up at home that could physically have been set up at the employer's premises does not meet the factor. Ordinary desk work, however genuinely remote, will not get there.
The six secondary factors, in substance. The home office is a requirement or condition of employment. The employer has a bona fide business purpose for an office in that locality. Some of the core duties of the job are performed there. Clients, patients or customers are met there on a regular and continuous basis. The employer does not provide designated office space or other regular work accommodations at one of its regular places of business. And the employer reimburses substantially all of the home office expenses, or pays a fair rental value and furnishes substantially all the supplies and equipment. On that last one the guidance supplies a number: "substantially all of the expenses means 80% or more of the expenses."
The ten other factors are physical and unglamorous, which is the point of them. A separate telephone line and listing for the home office. The home address and phone number on the employer's letterhead or business cards. An area of the home used exclusively for the employer's business and separate from the living area. Inventory or product samples kept there where the employer sells at wholesale or retail. The employer's business records stored there. A sign indicating a place of business of the employer. The home office appearing in the employer's advertising. Coverage by a business insurance policy or a business rider on the homeowner's policy. The employee actually claiming a federal home office deduction. And the employee not being an officer of the company.
What counts as a working day is defined narrowly and matters as much as the factors. A normal work day means "any day that the taxpayer performed the usual duties of his or her job," and the guidance adds that "responding to occasional phone calls or emails, reading professional journals or being available if needed does not constitute performing the usual duties." A day spent that way is a nonworking day, which leaves it out of both sides of the fraction rather than counting against the taxpayer.
The rule reaches local taxes as well. New York applies the same analysis to the Yonkers nonresident earnings tax, so the question is not confined to the state-level income tax. For a part-year resident, the test applies only to the nonresident portion of the year, and the day count is taken over that period alone.
Which states apply a version of it is genuinely a moving target, and some versions are conditional. Three that can each be cited to their own law or revenue department: New York, whose rule is unconditional and is the one described above; Connecticut, whose Circular CT states that "residents of states with a 'convenience of the employer' test will be subject to similar rules for work performed for a Connecticut employer"; and New Jersey, which added a comparable provision to N.J.S. 54A:5-8 in 2023, applying a similar New Jersey sourcing rule where a nonresident's own state of residence sources compensation to the employer's location on convenience grounds. Other states apply versions of the rule, and states have both adopted and dropped it, so the current position is a question for the revenue department of the state the employer sits in rather than something to take from any list, including this one.