510/511E: Application for Extension to File Pass-Through Entity (2025)
Maryland · Comptroller of Maryland · Used for tax years 2025
Maryland Form 510/511E requests an extension to file a pass-through entity income tax return, Form 510 or Form 511. It reports expected tax liability, estimated tax payments, and any tax paid with the extension. The extension gives you more time to file, but not more time to pay.
Who files this form
Use Form 510/511E to pay tax due when requesting an extension to file Maryland Form 510 or Form 511. Also use it if this is the entity’s first filing, even if no tax is due.
The form lists these entity types:
- S corporation
- Partnership
- Limited liability company
- Business trust
Do not use this form for corporations other than S corporations, entities filing a composite return, or employer withholding tax. Composite return filers use Form EL102B.
When it's due
For tax year 2025, file Form 510/511E by the 15th day of the fourth month following the close of the tax year for all pass-through entities.
An automatic extension is granted if the form is filed by the original due date. Extensions are allowed for up to seven months for S corporations and up to six months for other pass-through entities, measured from the original due date.
The extension gives you more time to file, not more time to pay the tax due.
What you'll need
Have the following information and forms available:
- The entity’s exact name, any “Trading As” (T/A) name, mailing address, and entity type.
- The federal employer identification number (FEIN). If you have applied but have not received it, enter “APPLIED FOR” and the application date.
- The beginning and ending dates if you use a non-calendar tax year. Use the same tax period as the federal return.
- Form 510 or Form 511 to use as a worksheet for expected tax liability.
- The total Maryland estimated tax paid with Form 510/511D for the tax year.
- The Box A or Box B choice made on the first filing for the tax year, if you have already filed.
If paying by mail, include a check or money order. If filing by phone, have the completed form available during the call.
How to file
Complete the entity information, select Box A or Box B, and complete the Tax Payment Worksheet:
- Enter the expected nonresident or electing PTE tax on line 1, using Form 510 or Form 511 as a worksheet.
- Enter Maryland estimated tax paid with Form 510/511D on line 2.
- Subtract line 2 from line 1. Line 3 is the tax to pay with the extension.
If line 3 is zero:
- File online at https://interactive.marylandtaxes.gov/business/Extension/busdefault.asp.
- Telefile at 410-260-7829 from Central Maryland or 1-800-260-3664 from elsewhere. Service is available 24 hours a day, seven days a week.
- File electronically through Modernized Electronic Filing (MeF), using a provider approved by the IRS and Revenue Administration Division.
- If this is the entity’s first filing, mail Form 510/511E even if no tax is due.
If line 3 shows tax due: file through MeF or mail the completed form with a check or money order to:
Comptroller of Maryland
Revenue Administration Division
110 Carroll Street
Annapolis, MD 21411-0001
Make the check or money order payable to Comptroller of Maryland. Include the FEIN, tax year, and tax type on the payment in blue or black ink. Do not send cash.
If you file online or electronically, do not mail Form 510/511E. Keep it with the company’s records.
Common mistakes
- Treating the extension as extra time to pay. It extends only the filing time. An unpaid liability disclosed on the return may result in penalties and interest in addition to the tax.
- Leaving the election unclear. You must select either Box A or Box B. The choice on the first filing is irrevocable for the tax year, and later filings must match it. On a first filing, checking neither box is treated as choosing to pay only for nonresident members; checking both is treated as electing to pay on all members’ shares.
- Mailing an unnecessary paper form. If no additional tax is due, do not mail it unless this is the entity’s first filing. Do not mail a duplicate after filing online or electronically.
- Leaving identifying information off the payment. Omitting the FEIN, tax year, or tax type delays payment processing. Use blue or black ink, and do not send cash.
- Missing the address or first-filer checkbox. Check the indicated box if you are a first-time filer or your mailing address has changed.
Questions people ask
What is the difference between Box A and Box B?
Box A elects to pay tax at the entity level on all members’ shares and requires Form 511 as the year-end return. Box B is for paying tax only on behalf of nonresident members and requires Form 510 as the year-end return.
Can I change my election on this extension?
No. The choice made on the first filing for the tax year is irrevocable. If you previously filed Form 510/511D for the tax year, this extension must match the choice on the first Form 510/511D.
Do I mail the form if no tax is due?
Generally, no. Use the online, telephone, or electronic filing options. However, if this is the entity’s first filing, mail Form 510/511E even if no tax is due.
What if the entity does not have a FEIN yet?
If you have applied, enter “APPLIED FOR” followed by the application date. If you have not applied, the instructions say to do so immediately.