Last updated: September 2026

State Tax Reciprocity Agreements: What Employers Must Withhold

State tax reciprocity only helps the employee who hands you a signed exemption certificate.

The theory is clean. A work state exempts a nonresident employee from its income tax, and the home state withholds instead. One paycheck, one state, one W-2 line.

The practice is messier, because the agreement only kicks in after the employee files that certificate. Until the form is in your payroll file, you withhold for the work state anyway.

How a reciprocal agreement actually works in payroll

Picture a welder who lives in Camden, New Jersey and drives across the bridge to a shop in Philadelphia. Pennsylvania and New Jersey have a deal that dates back to 1977. Without the deal, the welder owes PA income tax on every hour worked and then claims a credit back home on Schedule NJ-COJ. With the deal, Pennsylvania steps aside and New Jersey collects the state income tax.

The employer is the hinge. You run the paycheck. You pick the withholding state. You file the quarterly returns that tell each revenue department who got what.

One state in, one state out.

The mechanics look simple until you remember that reciprocity is opt-in at the employee level. A PA employer hiring a NJ resident does not automatically stop withholding Pennsylvania tax. The worker has to submit Form REV-419 (Employee's Nonwithholding Application) and check the box for New Jersey residence. No form, no exemption. You keep sending money to Harrisburg.

The active reciprocity pairs in 2026

Here are the agreements currently in force.

Mid-Atlantic cluster

The Mid-Atlantic cluster runs through Pennsylvania and its neighbors. Pennsylvania holds agreements with New Jersey, Ohio, Virginia, West Virginia, Maryland, and Indiana. Maryland layers on its own deals with Pennsylvania, Virginia, West Virginia, and the District of Columbia. Virginia pairs with Maryland, Washington DC, Pennsylvania, West Virginia, and Kentucky. The District of Columbia is unique in the whole system: it exempts any nonresident worker from DC income tax, not just commuters from Maryland and Virginia.

Midwest cluster

The Midwest cluster is denser. Illinois pairs with Iowa, Kentucky, Michigan, and Wisconsin. Indiana runs agreements with Kentucky, Michigan, Ohio, Pennsylvania, and Wisconsin. Kentucky carries the longest roster, covering seven neighbors: Illinois, Indiana, Michigan, Ohio, Virginia, West Virginia, and Wisconsin.

Michigan has deals with Illinois, Indiana, Kentucky, Minnesota, Ohio, and Wisconsin. Minnesota is narrower, with only Michigan and North Dakota. Ohio pairs with Indiana, Kentucky, Michigan, Pennsylvania, and West Virginia. Wisconsin rounds out the cluster with Illinois, Indiana, Kentucky, and Michigan.

Plains and mountain

The Plains and mountain section is small. North Dakota keeps deals with Minnesota and Montana. Montana reciprocates only with North Dakota. Iowa holds a single pair with Illinois.

New York is not on the list. Neither is California, Massachusetts, Connecticut, or Oregon. If you employ a New York resident working in New Jersey, both states want a piece and the worker claims a credit for the double taxation. No shortcut exists.

The certificate the employee must file

Every pair uses its own form, and the deadlines differ. Get the wrong version and the exemption does not apply.

In the Mid-Atlantic, Pennsylvania uses Form REV-419, and the employer sends a copy to the Department of Revenue when the employee claims residence in a reciprocal state. New Jersey uses Form NJ-165 for PA residents working in NJ. Maryland asks for Form MW507 with the nonresident exemption box checked. Virginia runs on Form VA-4, West Virginia on Form WV/IT-104NR, and Washington DC on Form D-4A.

Across the Midwest, Ohio collects Form IT 4, which replaced Form IT 4NR, from residents of the five reciprocal states. Michigan accepts the MI-W4 with line 8b completed. Indiana uses the WH-47 Certificate of Residence, Illinois the IL-W-5-NR, Kentucky the 42A809, and Wisconsin the W-220.

On the northern plains, Minnesota requires Form MWR, North Dakota requires Form NDW-R, and Montana requires Form MW-4 with the North Dakota resident exemption claimed.

Store the signed certificate in the employee's payroll file the same way you store the federal W-4. Several states require a new certificate every year. Minnesota wants Form MWR by February 28 each year, or within 30 days after the employee starts work or changes residence if that is later. North Dakota and Virginia also require a new form each year. Montana requires a new MW-4 each year, or the employer begins withholding.

What happens when there is no agreement

No reciprocity means dual taxation on paper, single taxation in practice, and a confused employee at tax time.

The work state taxes the wages because the income was earned inside its borders. The home state taxes the same wages because resident states tax worldwide income. The worker then claims a credit on the resident return for taxes paid elsewhere, on a form such as New York’s IT-112-R or New Jersey’s Schedule NJ-COJ. The total bill roughly equals the higher of the two rates.

Roughly. Not exactly. Credits are capped at what the home state would have charged on the same income. If the worker lives in a low-tax state and works in a high-tax state, part of the work-state tax is not recoverable.

Statutory residents are a separate problem. New York treats a worker domiciled elsewhere as a resident if the worker maintains a permanent place of abode in New York for substantially all of the year and spends 184 days or more there, so both states can tax the worker as a resident.

The convenience of the employer rule

Reciprocity and the convenience rule solve different problems. A reciprocal agreement lets a resident of one state claim exemption from the other state’s withholding. A convenience rule runs the other way: a day a nonresident employee spends working from home counts as a day worked in the employer’s state unless the employer required it. New Jersey’s rule does not apply to Pennsylvania residents who work in New Jersey, because of the reciprocal agreement between the two states.

The guide to the convenience of the employer rule covers which states apply it and how New York’s test works.

The gotcha that wrecks employers every year

Reciprocity is opt-in per employee, not automatic per company.

A reciprocal agreement between two states gives an employee the right to claim exemption from the work state’s income tax withholding, but the exemption takes effect only after that specific employee files the work state’s nonwithholding certificate with the employer. An employer in Pennsylvania with three New Jersey residents already on file has no coverage for a fourth New Jersey hire. Until that fourth employee’s certificate is signed and on file, Pennsylvania withholding is still required.

The exposure sits with the employer. When withholding stops without a certificate on file, Pennsylvania holds the employer liable for the tax it was required to withhold, plus penalties and interest, whether or not it collects that tax from the employee.

The form creates the exemption. Not the address. Not the assumption. Not the friendly handshake between states.

One more trap worth naming: reciprocity applies to compensation only. W-2 wages, yes. 1099 contractor pay, no. Retirement income gets a separate and stronger protection from federal law. Under 4 U.S.C. 114, no state may tax the retirement income of a person who is not a resident or domiciliary of that state, so a retiree living in Pennsylvania who draws a pension from a former New Jersey employer owes no New Jersey tax on it. That protection comes from federal law rather than from the reciprocal agreement, and it reaches qualified plans, SEPs, IRAs, 403(b) annuities, section 457 plans, and governmental plans.

Secondary trap: local taxes are separate. Indiana county taxes still apply to an employee exempt from Indiana state tax under reciprocity. Maryland’s exemption for Pennsylvania residents covers only the state portion of withholding, so the Maryland county rate still applies unless the employee qualifies for a local exemption. A New Jersey resident working in Philadelphia pays no Pennsylvania state tax under REV-419 but still owes the Philadelphia nonresident wage tax. The city sets separate resident and nonresident rates, each taking effect on July 1, so the current rate has to be confirmed with the Philadelphia Department of Revenue before it is configured in payroll. The city is not a party to the state level agreement.

Your action steps this week

Audit every employee whose residence address and work location cross a state border. Pull the list from your HRIS or, if you do not have one, from your W-4 files.

For each one, confirm three things: whether an agreement exists between the two states, whether the employee has filed the correct exemption certificate, and whether the certificate needs renewal this year. If any answer is no or unknown, fix it before the next payroll run.

Next, map your remote workers against the convenience of the employer rule.

Pull the current agreement list directly from the Pennsylvania Department of Revenue or your own state's revenue site. Bookmark it. The 1977 Pennsylvania and New Jersey agreement lets either state end it with 90 days notice before the start of the next tax year. New Jersey announced in early September 2016 that it would end its Pennsylvania agreement on January 1, 2017, then reversed that decision in late November.

Finally, review the payroll tax fundamentals and the full multi-state withholding rules.

This is not legal or financial advice. Consult a qualified professional for your specific situation.