Multi-State Remote Employees: Payroll Tax Registration Steps

A historic worker's payroll book. Photo: Dmitry Makeev, public domain, via Wikimedia Commons.

Hiring your first remote employee in another state takes a recruiter a week. Untangling what that hire does to your payroll can take a quarter. Suddenly the question is not just what the person earns, but which state gets a share of the withholding, which state's unemployment system covers them, and who you have to register with before the first paycheck goes out.

To register for payroll taxes for a remote employee in another state, first confirm where the person physically works and lives. Then decide which state's income tax withholding rules apply, decide which state's unemployment insurance law covers the job, and register with that state's revenue department and workforce agency. Rules differ by state. California, for example, says employers must register within 15 days of paying more than $100 in wages in a calendar quarter, while Illinois, New York and Massachusetts each have their own withholding rules.

By the Decision Makers Hub editorial team. Last updated November 2026. This article is general information, not tax or legal advice. It summarizes state agency pages for California, Colorado, Illinois, Massachusetts and New York, plus the U.S. Department of Labor. It is not a 50 state guide, so confirm the rules for each state where your employees work.

Key takeaways

• Most multi-state payroll work comes down to two registrations: state income tax withholding and state unemployment insurance.
• The work location usually drives withholding, but the home state, reciprocity agreements and special rules such as New York's telecommuting rule can change the answer.
• Unemployment insurance follows a four part test from the Department of Labor, applied in order: localization, base of operations, direction and control, then residence.
• Start the paperwork before the first paycheck. California gives employers 15 days after the wage threshold is met.
• Keep each state's forms, account numbers and filing dates in one tracker.

What do you have to register for?

Your federal setup does not change. You keep one employer identification number and the same federal deposit schedule we explained in our payroll compliance checklist. What changes is the state layer.

Registration	Who handles it	What it covers
State income tax withholding account	The state revenue or tax department	Withholding from the employee's pay and the returns you file with the state
State unemployment insurance account	The state workforce or labor agency	Unemployment tax for the employee, reported where the job is covered
Other state or local accounts	Varies by state	Programs that differ widely, so check each state's employer guide

The employee adds a piece of the puzzle too: the federal Form W-4 and any state form. Our guide to Form W-4 for employers covers the federal side.

How do you decide which state gets the withholding?

Start with where the employee physically does the work, then check the home state. A few official examples show how much the rules vary.

State	What the state says	Source type
California	Employers must register within 15 days of paying more than $100 in wages in a calendar quarter	EDD employer registration page
Colorado	Anyone required to withhold Colorado income tax must apply as a withholding tax agent, and out-of-state businesses should use the Wage Withholding Account Application (CR 0100)	Colorado Department of Revenue
Massachusetts	A non-Massachusetts employer that conducts business or maintains an office in the state must withhold Massachusetts tax, and where the employee works does not change that	Mass.gov withholding guide
Illinois	Reciprocal withholding agreements with Iowa, Kentucky, Michigan and Wisconsin let a resident of those states give the employer Form IL-W-5-NR to claim an exemption from Illinois withholding	Illinois Department of Revenue
New York	For a nonresident whose primary office is in New York, days spent telecommuting are considered days worked in the state unless the employer has established a bona fide employer office at the telecommuting location	NY Tax Department FAQ

Read those rows as examples, not a map of the country. The point is that a single remote hire can trigger three different questions: does the work state require withholding, does the home state also tax the wages, and does a reciprocity agreement or telecommuting rule change who you withhold for. Congress has also seen proposals to set a uniform threshold, including the Mobile Workforce State Income Tax Simplification Act (S.1443 in the 119th Congress, per Congress.gov), but we did not find evidence it has become law, so state rules still apply.

Which state's unemployment insurance covers the job?

Unemployment insurance does not follow the same logic as income tax withholding. The Department of Labor describes four tests applied in order to decide which state's law covers a worker who works in more than one state.

Order	Test	Question it asks
1	Localization	Is the service localized in one state, with work elsewhere only incidental or temporary?
2	Base of operations	If not, does the worker perform some service in the state where their base of operations is?
3	Direction and control	If not, is the work directed and controlled from a state where some service is performed?
4	Residence	If none of the above decides it, does the worker perform some service in the state where they live?

For a fully remote employee who works from home in one state, the first test usually settles it: the service is localized there. Hybrid and traveling employees are where the later tests come in. This is the same unemployment system behind the federal piece we described in our guide to employer only payroll taxes, FUTA and SUTA, and the state you register in can matter for federal credits too, as we explain in our FUTA credit reduction article.

What are the registration steps?

1. Confirm the facts. Get the employee's home address, the address where they actually work, and an expected schedule. If they travel or split time, document it.
2. Check the work state's withholding rule. Look for a threshold, an out-of-state employer registration form, and any telecommuting rule.
3. Check the home state and reciprocity. If the employee lives in a different state, see whether the two states have a reciprocity agreement and what form the employee must sign.
4. Apply the unemployment tests. Use the Department of Labor's four part order to decide which state's unemployment system covers the job.
5. Register with the state agencies. Open a withholding account with the revenue department and an unemployment account with the workforce agency. Build in lead time, and in California start within 15 days of meeting the wage threshold.
6. Collect forms and set up payroll. Get the federal Form W-4, any state withholding form, and enter the state account numbers and filing frequencies in your payroll system.
7. Calendar the filings. Add the state return and payment dates to your compliance calendar, next to your quarterly federal filings.
8. Revisit when something changes. A move, a new work location or a change in travel patterns can change the answer.

A worked scenario (illustrative)

This scenario is made up to show the sequence. You are headquartered in one state and hire a bookkeeper who works full time from home in Colorado. First, you confirm the home office address is the work location. Second, because Colorado requires anyone who must withhold Colorado income tax to apply as a withholding tax agent, and says out-of-state businesses should complete the CR 0100 application, you register there before the first paycheck. Third, you apply the unemployment tests: all the work happens in Colorado, so the service is localized there, and you set up unemployment reporting with the state. Fourth, you add the Colorado filing dates to your calendar. If the same bookkeeper later moved to Illinois, you would start the process again for Illinois.

How do other payroll rules change with remote workers?

Registration is only the start. Pay timing, final pay and leave rules also follow the employee's work state, as we showed in our guide to final paycheck laws by state. Scheduling rules vary too, which we covered in our piece on predictive scheduling laws. For the full reading list, see our payroll and compliance guides.

Common mistakes to avoid

• Withholding only for the headquarters state because that is where payroll is run.
• Waiting until the first return is due to register. Some states set a registration deadline measured from the first wages.
• Ignoring reciprocity paperwork. In Illinois, an eligible resident of a reciprocal state needs to give the employer Form IL-W-5-NR to stop Illinois withholding.
• Assuming a fully remote employee is exempt from a state's telecommuting rule. New York's test depends on whether you have a bona fide employer office at the telecommuting location.
• Forgetting to update the registration when an employee moves.

Frequently asked questions

Do I have to register in a state if one employee works there remotely?

Often yes, but it depends on the state. Colorado requires anyone who must withhold Colorado income tax to apply as a withholding tax agent, and Massachusetts requires a non-Massachusetts employer that conducts business or maintains an office there to withhold. Check each state's rules.

How soon do I need to register?

It varies. California says to register within 15 days of paying more than $100 in wages in a calendar quarter. Other states set their own timing, so start before the first paycheck.

Which state's unemployment insurance applies to a remote worker?

The Department of Labor describes four tests applied in order: localization, base of operations, direction and control, and residence. A worker who does all their work in one state is generally covered there.

What is a reciprocity agreement?

It is an agreement between states that lets a resident of one state avoid withholding in the other. Illinois, for example, has reciprocal agreements with Iowa, Kentucky, Michigan and Wisconsin, and the employee gives the employer Form IL-W-5-NR.

Does a federal law set one national rule?

Not that we found. Congress has considered the Mobile Workforce State Income Tax Simplification Act, but we did not find evidence that it has been enacted, so state rules apply.

The bottom line

Treat every remote hire in a new state as a mini project: confirm the facts, check withholding and unemployment separately, register early, and write the accounts down. The first one takes time. By the third, you will have a repeatable checklist.

Sources

• California EDD: Step 1, Register as an Employer
• Colorado Department of Revenue: Withholding Accounts
• Mass.gov: Withholding Tax Guide
• Illinois Department of Revenue: Form IL-W-5-NR
• New York State Tax Department: Nonresident, residency and telecommuting FAQ
• U.S. Department of Labor: UIPL 20-04, Attachment 1 (coverage tests)
• Congress.gov: S.1443, Mobile Workforce State Income Tax Simplification Act of 2025

This article is general information, not tax or legal advice. Consult a tax professional or the relevant state agencies before registering.