Maryland Business Tax Extension LLC / Partnership – S Corporation – C Corporation – Fiduciary
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Connect with a TaxPro →Maryland Business Tax Extension – LLC / Partnership
Form 510E | Maryland Pass-Through Entity Extension Request • LLC / PartnershipMaryland LLC & Partnership Tax Extension
Maryland LLCs and partnerships file their pass-through entity returns with the Maryland Comptroller. To extend the filing deadline from March 16, 2026 to September 15, 2026, a Maryland pass-through entity must submit Form 510E. Unlike some states, Maryland requires a separate state extension form–the federal IRS Form 7004 alone does not extend the Maryland deadline.
How the Extension Works
File Form 510E with the Maryland Comptroller before March 16, 2026. This extends the filing deadline to September 15, 2026. Pay any Maryland pass-through entity tax owed using Maryland’s online business file system or mail payment to: Comptroller of Maryland, Revenue Administration Division, Annapolis, MD 21411-0001. Note: Maryland also has a pass-through entity (PTE) election that may affect payment requirements.
Best Practices
- File Maryland Form 510E before March 16, 2026–a federal extension alone does not extend the Maryland LLC/partnership deadline.
- Pay any Maryland pass-through entity tax by March 16, 2026 through Maryland’s online portal or by mail.
- Review Maryland’s PTE election status before March 16, 2026 to confirm whether entity-level tax is owed.
- File the completed Maryland LLC or partnership return by September 15, 2026.
Working with a Tax Professional
LLC / Partnership returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your Maryland return is filed accurately and on time.
- Get matched with a verified U.S.-based CPA or Enrolled Agent
- Upload your business documents via secure drag-and-drop
- Review your return with transparent, upfront pricing
- Your TaxPro files the Maryland return by September 15, 2026
How to Pay
Maryland requires online payment for tax amounts of $750 or more. Submit electronically via the Maryland Online Tax Extension Payment portal. For amounts under $750, complete Form 510E | Maryland Pass-Through Entity Extension Request and mail with your payment.
Maryland Online Payment Portal
Submit electronically through the Maryland Online Tax Extension Payment system. Required for all payments $750 and above.
Form 510E | Maryland Pass-Through Entity Extension Request by Check
Download Form 510E | Maryland Pass-Through Entity Extension Request and mail with your check or money order. Include your EIN and tax year on the check.
Revenue Administration Division
Annapolis, MD 21411-0001
Late Filing & Payment Penalties
| Penalty Type | Amount |
|---|---|
| Failure to File | 10% of tax due or $50, whichever is greater, per month up to 25%. |
| Failure to Pay | 10% of unpaid tax. |
LLC / Partnership Quick Reference
| State Abbreviation | MD |
| Entity Type | LLC / Partnership |
| Extension Status | Automatic with approved IRS Form 7004 |
| Original Filing Deadline | March 16, 2026 |
| Extended Filing Deadline | September 15, 2026 |
| Payment Due | March 16, 2026 (100% of tax owed) |
| Payment Form | Form 510E | Maryland Pass-Through Entity Extension Request |
| Online Payment | Maryland Online Tax Extension Payment |
| State Agency | Maryland Comptroller |
| Failure to File Penalty | 10% of tax due or $50, whichever is greater, per month up to 25%. |
| Failure to Pay Penalty | 10% of unpaid tax. |
Maryland Business Tax Extension – S Corporation
Form 510E | Maryland Pass-Through Entity Extension Request • S CorporationMaryland S Corporation Tax Extension
Maryland S corporations file pass-through entity returns with the Maryland Comptroller. A 7-month extension is available–moving the deadline from March 16, 2026 to September 15, 2026–upon filing Maryland Form 510E. The federal IRS Form 7004 does not extend the Maryland S corporation return on its own.
How the Extension Works
File Form 510E with the Maryland Comptroller before March 16, 2026 to extend to September 15, 2026. Pay any Maryland S corporation or PTE tax owed using Maryland’s online business portal or mail to: Comptroller of Maryland, Revenue Administration Division, Annapolis, MD 21411-0001. Note that Maryland S corporations may be subject to the PTE election tax.
Best Practices
- File Maryland Form 510E before March 16, 2026–federal Form 7004 alone does not extend the Maryland S corp deadline.
- Pay Maryland S corporation or PTE tax by March 16, 2026 through Maryland’s online portal or by mail.
- Confirm PTE election status and whether entity-level tax is owed before March 16, 2026.
- File the completed Maryland S corporation return by September 15, 2026.
Working with a Tax Professional
S Corporation returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your Maryland return is filed accurately and on time.
- Get matched with a verified U.S.-based CPA or Enrolled Agent
- Upload your business documents via secure drag-and-drop
- Review your return with transparent, upfront pricing
- Your TaxPro files the Maryland return by September 15, 2026
How to Pay
Maryland requires online payment for tax amounts of $750 or more. Submit electronically via the Maryland Online Tax Extension Payment portal. For amounts under $750, complete Form 510E | Maryland Pass-Through Entity Extension Request and mail with your payment.
Maryland Online Payment Portal
Submit electronically through the Maryland Online Tax Extension Payment system. Required for all payments $750 and above.
Form 510E | Maryland Pass-Through Entity Extension Request by Check
Download Form 510E | Maryland Pass-Through Entity Extension Request and mail with your check or money order. Include your EIN and tax year on the check.
Revenue Administration Division
Annapolis, MD 21411-0001
Late Filing & Payment Penalties
| Penalty Type | Amount |
|---|---|
| Failure to File | 10% of tax due or $50, whichever is greater, per month up to 25%. |
| Failure to Pay | 10% of unpaid tax. |
S Corporation Quick Reference
| State Abbreviation | MD |
| Entity Type | S Corporation |
| Extension Status | Automatic with approved IRS Form 7004 |
| Original Filing Deadline | March 16, 2026 |
| Extended Filing Deadline | September 15, 2026 |
| Payment Due | March 16, 2026 (100% of tax owed) |
| Payment Form | Form 510E | Maryland Pass-Through Entity Extension Request |
| Online Payment | Maryland Online Tax Extension Payment |
| State Agency | Maryland Comptroller |
| Failure to File Penalty | 10% of tax due or $50, whichever is greater, per month up to 25%. |
| Failure to Pay Penalty | 10% of unpaid tax. |
Maryland Business Tax Extension – C Corporation
Form 500E | Maryland Corporation Income Tax Extension • C CorporationMaryland C Corporation Tax Extension
Maryland C corporations file with the Maryland Comptroller and pay Maryland corporate income tax. Maryland provides a 7-month extension–moving the C corporation deadline from April 15, 2026 to November 15, 2026–upon filing Maryland Form 500E. A federal extension alone does not extend the Maryland C corporation return.
How the Extension Works
File Maryland Form 500E before April 15, 2026 to obtain the 7-month extension to November 15, 2026. Pay any Maryland corporate income tax owed using Maryland’s online business portal or mail to: Comptroller of Maryland, Revenue Administration Division, Annapolis, MD 21411-0001.
Best Practices
- File Maryland Form 500E before April 15, 2026–the federal extension does not extend the Maryland C corp deadline.
- Pay Maryland corporate income tax by April 15, 2026 through Maryland’s online portal or by mail.
- Do not confuse Form 500E (C corporation) with Form 510E (pass-through entity)–use the correct form.
- File the completed Maryland C corporation return by November 15, 2026.
Working with a Tax Professional
C Corporation returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your Maryland return is filed accurately and on time.
- Get matched with a verified U.S.-based CPA or Enrolled Agent
- Upload your business documents via secure drag-and-drop
- Review your return with transparent, upfront pricing
- Your TaxPro files the Maryland return by November 15, 2026
How to Pay
Maryland requires online payment for tax amounts of $750 or more. Submit electronically via the Maryland Online Tax Extension Payment portal. For amounts under $750, complete Form 500E | Maryland Corporation Income Tax Extension and mail with your payment.
Maryland Online Payment Portal
Submit electronically through the Maryland Online Tax Extension Payment system. Required for all payments $750 and above.
Form 500E | Maryland Corporation Income Tax Extension by Check
Download Form 500E | Maryland Corporation Income Tax Extension and mail with your check or money order. Include your EIN and tax year on the check.
Revenue Administration Division
Annapolis, MD 21411-0001
Late Filing & Payment Penalties
| Penalty Type | Amount |
|---|---|
| Failure to File | 10% of tax due or $50, whichever is greater, per month up to 25%. |
| Failure to Pay | 10% of unpaid tax. |
C Corporation Quick Reference
| State Abbreviation | MD |
| Entity Type | C Corporation |
| Extension Status | Automatic with approved IRS Form 7004 |
| Original Filing Deadline | April 15, 2026 |
| Extended Filing Deadline | November 15, 2026 |
| Payment Due | April 15, 2026 (100% of tax owed) |
| Payment Form | Form 500E | Maryland Corporation Income Tax Extension |
| Online Payment | Maryland Online Tax Extension Payment |
| State Agency | Maryland Comptroller |
| Failure to File Penalty | 10% of tax due or $50, whichever is greater, per month up to 25%. |
| Failure to Pay Penalty | 10% of unpaid tax. |
Maryland Business Tax Extension – Fiduciary
Form 504E | Maryland Fiduciary Income Tax Extension • FiduciaryMaryland Fiduciary Tax Extension
Maryland fiduciary returns (trusts and estates) are filed with the Maryland Comptroller. A 7-month extension to October 15, 2026 is available by filing Maryland Form 504E before the April 15, 2026 original deadline. The federal extension alone does not extend the Maryland fiduciary return.
How the Extension Works
File Maryland Form 504E before April 15, 2026 to extend the fiduciary filing deadline to October 15, 2026. Pay any Maryland fiduciary income tax owed through Maryland’s online portal or mail to: Comptroller of Maryland, Revenue Administration Division, Annapolis, MD 21411-0001.
Best Practices
- File Maryland Form 504E before April 15, 2026–the federal extension does not extend the Maryland fiduciary deadline.
- Pay Maryland fiduciary income tax by April 15, 2026 through Maryland’s online portal or by mail.
- Use Form 504E specifically–not Form 500E or Form 510E%#8212;for Maryland fiduciary extensions.
- File the completed Maryland fiduciary return by October 15, 2026.
Working with a Tax Professional
Fiduciary returns carry unique complexities – a licensed CPA or Enrolled Agent can navigate the details and ensure your Maryland return is filed accurately and on time.
- Get matched with a verified U.S.-based CPA or Enrolled Agent
- Upload your business documents via secure drag-and-drop
- Review your return with transparent, upfront pricing
- Your TaxPro files the Maryland return by October 15, 2026
How to Pay
Maryland requires online payment for tax amounts of $750 or more. Submit electronically via the Maryland Online Tax Extension Payment portal. For amounts under $750, complete Form 504E | Maryland Fiduciary Income Tax Extension and mail with your payment.
Maryland Online Payment Portal
Submit electronically through the Maryland Online Tax Extension Payment system. Required for all payments $750 and above.
Form 504E | Maryland Fiduciary Income Tax Extension by Check
Download Form 504E | Maryland Fiduciary Income Tax Extension and mail with your check or money order. Include your EIN and tax year on the check.
Revenue Administration Division
Annapolis, MD 21411-0001
Late Filing & Payment Penalties
| Penalty Type | Amount |
|---|---|
| Failure to File | 10% of tax due or $50, whichever is greater, per month up to 25%. |
| Failure to Pay | 10% of unpaid tax. |
Fiduciary Quick Reference
| State Abbreviation | MD |
| Entity Type | Fiduciary |
| Extension Status | Automatic with approved IRS Form 7004 |
| Original Filing Deadline | April 15, 2026 |
| Extended Filing Deadline | October 15, 2026 |
| Payment Due | April 15, 2026 (100% of tax owed) |
| Payment Form | Form 504E | Maryland Fiduciary Income Tax Extension |
| Online Payment | Maryland Online Tax Extension Payment |
| State Agency | Maryland Comptroller |
| Failure to File Penalty | 10% of tax due or $50, whichever is greater, per month up to 25%. |
| Failure to Pay Penalty | 10% of unpaid tax. |
Extended? Your Maryland Business Return Deadline Is Coming Up.
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