Mississippi Payroll Tax and Registration Guide

Use this checklist to make sure you’ve covered everything required to set up your account as a Mississippi employer so OnPay can accurately file and pay taxes on your behalf: 

OnPay handles the filing of all state and local taxes for businesses in Mississippi, including:

If you are an existing employer who has previously run payroll in Mississippi, you likely already have the IDs and online accounts needed for OnPay to process your tax filings. 

If you are a new employer in Mississippi, you will need to register your business with the Mississippi Department of Revenue and Mississippi Department of Employment Security. This must be completed for OnPay to be able to file and pay your Mississippi taxes.

Withholding Tax Account Number and Deposit Frequency

Existing Mississippi Employer: 

You can find your Withholding Tax Account Number on notices received from the Mississippi Department of Revenue. If you cannot locate this number, please call the agency at 601-923-7088.

New Mississippi Employer: Register with the Mississippi Department of Revenue 

• Register online with the Mississippi Department of Revenue. (Click “Register for taxes”.)
• You should receive your account number immediately after completing the online registration.

Mississippi Letter ID

All Mississippi Employers: 

• The identity validation and PIN verification letters are used by the Mississippi Department of Revenue to prevent fraud
• If you cannot find one of these letters, contact the Department Of Revenue at (601) 923-7700. They're available from 8-5, Monday through Friday.
• More information on ID Validation Letters

Mississippi Employer Account Number and Contribution Tax Rate

Existing Mississippi Employer: 

• You can find your Employer Account Number and Contribution Rate on the Contribution Tax Rate Notice sent by the Mississippi Department of Employment Security.
• If you cannot find these numbers, please call the agency at 601-923-7700.
• Rates can be up to 5.4% for SUTA, with a $14,000 wage base.

New Mississippi Employer: Register with the Mississippi Department of Employment Security

• Register online with the Mississippi Department of Employment Security.
• You should receive your Employer Account Number and Contribution Tax Rate immediately after completing the online registration.
• New employer SUI rates begin at 1% for the first year, 1.10% for the second year, and 1.20% for the third year, after which the employer's rate can range up to 5.4%, as listed above, with a $14,000 wage base.

OnPay works with government entities on your behalf, reporting new hires to state labor departments, calculating tax rates, and filing financial reports. To do this effectively, you will need to add OnPay as your third party agent with the Department of Employment Security, or MDES.

How to add OnPay to your existing MDES account:

1. Log into MDES with your existing MDES info
2. Go to My User Profile
3. Click Add User
4. New User name: "Caroline Brown"
5. Abilities of: "Account Maintenance" and "Tax Reporting".
6. Once you've added Caroline as a user, email us at hello@onpay.com and let us know you've completed authorizing our TPA access.

Power of Attorney

You will also need to grant OnPay power of attorney by following the instructions in this article.