How to Complete PS Form 4: Employee’s City or County Withholding Certificate

PS Form 4, the Employee’s City or County Withholding Certificate, is the paper form U.S. Postal Service employees use to start, change, or stop local income or occupational tax withholding from their pay. Fill it out, sign it, and mail it to the HR Shared Service Center at PO Box 970400, Greensboro, NC 27497-0400. It handles city and county taxes only; federal and state withholding are changed through PostalEASE.¹

Who Needs to File It

You need this form if you live or work somewhere that levies a local income tax, occupational tax, or similar assessment and that jurisdiction has a withholding agreement with the U.S. Department of the Treasury. The Postal Service collects local taxes only where such an agreement exists.² As a USPS employee, you’re personally responsible for making sure the right local tax comes out of your check. If a qualifying tax isn’t being withheld, submit a PS Form 4 right away.

What to Gather Before You Fill It Out

Have these ready:

Your full legal name as it appears in your personnel file
Your Social Security number
Your current home address, including ZIP code
The three-digit local tax code for your jurisdiction
The exemption or withholding details your locality requires (a number of exemptions, a flat dollar amount, or a percentage — this varies)

Finding Your Local Tax Code

Every jurisdiction with an active Treasury agreement is assigned a three-digit code, and you need it to complete the form. The Postal Service publishes the current list in the Postal Bulletin; the most recent version (Postal Bulletin 22693, dated January 8, 2026) covers jurisdictions in Alabama, Colorado, Delaware, Kentucky, Michigan, Missouri, New York, Ohio, Pennsylvania, and West Virginia.²

Some localities levy more than one local tax, each with its own code. Several Pennsylvania cities, for example, have separate codes for city income tax and local services tax, and Kentucky’s Boone County has separate codes for its ordinance tax and its mental health tax. If more than one applies to you, list each code.²

If you can’t find your city or county on the list, call the HRSSC at 877-477-3273, option 5, or contact your local taxing authority directly.³

Filling In the Form

Enter your name, Social Security number, and current home address. The address is not just paperwork; it determines which taxing jurisdiction applies to you. If you recently moved between cities, the new address could trigger a new local tax or eliminate an old one. Use where you actually live now, not a prior address.

The exemption and withholding section is where most people trip up. Some cities calculate withholding as a percentage of gross pay, others as a flat dollar amount per pay period, and others use a number of exemptions similar to a W-4. The form gives you space for these figures but doesn’t tell you what your locality requires. Check with your local tax office or read the ordinance so you enter the right rate and exemption count.

Sign and date the form. An unsigned form won’t be processed. Keep a photocopy before you mail it.

Where to Send It

Mail the completed, signed form to:

HR Shared Service Center
PO Box 970400
Greensboro, NC 27497-0400

There is no electronic option. PostalEASE handles federal W-4 and state withholding changes, but local tax withholding through PS Form 4 still requires paper submission by mail.¹

Check Your Paystub After Submission

Once the HRSSC processes the form, the local tax withholding should show up as a line item on your earnings statement. Look at each paystub after you submit and confirm the deduction is there and the amount is reasonable. If several pay periods pass with nothing withheld, call the HRSSC at 877-477-3273, option 5.³

Don’t let a missing deduction slide. The local taxing authority still expects the money whether or not USPS withheld it. If withholding never starts, you’ll owe the full amount when you file your local return, plus any interest or penalties for underpayment.

When to File a New PS Form 4

Submit a new form whenever your local tax situation changes. Common triggers:

Moving to a different city or county that has its own local tax
Transferring to a duty station in a jurisdiction with a different local tax
A change in your exemptions from marriage, dependents, or another life event
Moving out of a taxing jurisdiction and needing to stop the withholding

The Postal Bulletin periodically publishes updated code lists. If your jurisdiction’s code or tax type changes, a new form may be needed to keep the withholding accurate.²

If Your City or County Isn’t on the List

Not every locality with a local tax has a withholding agreement with the Treasury. Under 5 U.S.C. § 5520, only jurisdictions meeting the statutory requirements, including a threshold of 500 federal employees within their boundaries, can request an agreement.⁴ If your city or county isn’t on the Postal Bulletin list, the Postal Service will not withhold that tax, and PS Form 4 won’t help you.

You still owe the tax. Pay the local authority directly, usually through quarterly estimated payments or an annual return. Contact the city or county tax office for the schedule and payment method. The absence of payroll withholding doesn’t mean the tax doesn’t apply, and falling behind carries the same penalties as any other unpaid local tax.³

1
United States Postal Service. Maintain Up-to-Date Tax Withholding Information in PostalEASE
2
United States Postal Service. Local Tax Code Information
3
United States Postal Service. Local Tax Code Information
4
Office of the Law Revision Counsel. 5 USC 5520 – Withholding of City or County Income or Employment Taxes