Mississippi Compliance and Regulatory Resources

Withholding Registration

All employers are required to have an active withholding tax account number to file electronically with the Mississippi Department of Revenue (DOR).

Paychex must also be authorized as the Third-Party Administrator (TPA) on the account for filing quarterly returns, remitting payments, as well as making any adjustments to returns and payments on your behalf.

Register a New Business

1. Visit the Mississippi DOR site.
2. Under the Apply Online section, select Apply for Tax Accounts, Liquor Permits, Amusement Decals option.
3. Complete the registration process.
4. The withholding tax account number can be available immediately after completing the registration if all the information submitted is accurate.
   • MS Withholding Account Number can be in the following formats:
     • XXXX-XXXX or XXXXXXXX (8 Digits)
5. Enter your new account numbers in Paychex Flex to ensure your account is updated and email your registration confirmation document to your Paychex Service Professional.
   • Refer to the Updating Tax Agency IDs in Paychex Flex instructions to update the information in the application.
6. Refer to the Designating Paychex as Your Third-Party Administrator (TPA) section for instructions for assigning Paychex as the TPA for your account to submit quarterly returns and payments on your behalf.

Designating Paychex as Your Third-Party Administrator (TPA)

1. Complete the MS Power of Attorney (POA) form.
2. Email your registration confirmation document and POA form to your Paychex Service Professional.

Finding an Existing ID

If you have a Mississippi withholding ID but aren’t sure what it is, you should be able to find it on:

1. Online Mississippi DOR (Taxpayer Access Point) account
2. Any correspondence from the DOR.
3. Previously filed returns.

Additional Resources

• Mississippi Department of Revenue contact information
• Taxpayer Access Point Help | FAQs

State Unemployment Insurance (SUI) Registration

All employers are required to have an active state unemployment Insurance (SUI) account number to file electronically with the Mississippi Department of Employment Security (MDES). This can also be referred to as the Employer Account Number (EAN).

Register a New Business

1. Visit the ReEmployMS site.
2. Complete the registration process.
3. Once the registration is complete, you’ll receive a confirmation page. Take a screenshot of this page.
   • MS SUI Account Number can be in the following format:
     • XXXXXXXXXX (10 Digits)
4. Enter your new account numbers in Paychex Flex to ensure your account is updated and email your registration confirmation document to your Paychex Service Professional.
   • Refer to the Updating Tax Agency IDs in Paychex Flex instructions to update the information in the application.
5. Authorize Paychex as your Third-Party Administrator (TPA).
   • See the Designating Paychex as your Third-Party Administrator (TPA) section below for instructions.

Designating Paychex as your Third-Party Administrator (TPA)

MDES requires Professional Employer Organization (PEO) entities operating under a co-employment agreement to provide separate Powers of Attorney (POAs) and Third-Party Administrator (TPA) information from those required for non-PEO employers.

Please contact your Paychex Service Professional to confirm whether you should follow the PEO or Non-PEO Employer instructions and use the appropriate TPA instructions outlined below.

For Non-PEO Employers:

No Power of Attorney (POA) form or TPA actions required.

For PEO Employers:

1. Complete the MS Power of Attorney (POA) form.
2. Email your registration confirmation document and POA form to your Paychex Service Professional.

Finding an Existing ID

If you have a Mississippi SUI ID but aren’t sure what it is, you should be able to find it on:

1. Online ReEmployMS Account
2. Any correspondence from the MDES.
3. Previously filed returns.

Additional Resources

• Mississippi Department of Employment Security - Contact Information
• Employer FAQs