Maryland Business Tax Deadlines (2026)
Next: June 15, 2026 — Federal & Maryland Q2 Estimated Tax Payment
Next Deadline: June 15, 2026 — Federal & Maryland Q2 Estimated Tax Payment
Federal Tax Deadlines (2026)
| Form | Who Files | Due Date | Extension Deadline |
|---|---|---|---|
| Form 1040 (Schedule C) | Sole proprietors | April 15 | October 15 |
| Form 1065 | Partnerships, Multi-member LLCs | March 15 | September 15 |
| Form 1120-S | S-Corporations | March 15 | September 15 |
| Form 1120 | C-Corporations | April 15 | October 15 |
| Form 990 | Nonprofits | May 15 | November 15 |
| Estimated Taxes (Q1) | All | April 15 | — |
| Estimated Taxes (Q2) | All | June 15 | — |
| Estimated Taxes (Q3) | All | September 15 | — |
| Estimated Taxes (Q4) | All | January 15, 2027 | — |
Maryland State Tax Deadlines (2026)
| Tax Type | Due Date | Form/Filing | Notes |
|---|---|---|---|
| Individual Income Tax | April 15 | Form 502 | Rates 2%–5.75% + county tax |
| Corporate Income Tax | April 15 | Form 500 | 8.25% rate |
| S-Corp Return | March 15 | Form 510 | Pass-through |
| Partnership Return | March 15 | Form 510 | Pass-through entity |
| Pass-Through Entity Tax | April 15 | Form 511 | Elective PET |
| Sales Tax (Monthly) | 20th of following month | Via bFile | State rate 6% |
| Withholding Tax (Monthly/Quarterly) | 15th of following month | MW506 via bFile | Employers |
| Annual Report / Personal Property | April 15 | Filed with SDAT | Annual filing with Dept. of Assessments |
| Estimated Income Tax (Q1) | April 15 | Form 502D / 500D | — |
| Estimated Income Tax (Q2) | June 15 | Form 502D / 500D | — |
| Estimated Income Tax (Q3) | September 15 | Form 502D / 500D | — |
| Estimated Income Tax (Q4) | January 15, 2027 | Form 502D / 500D | — |
Quarterly Estimated Tax Deadlines in Maryland
Maryland follows the federal estimated tax payment schedule:
Estimated payments are required if you expect to owe $500 or more in Maryland income tax (state + county combined).
Maryland-Specific Tax Requirements
Maryland has a graduated individual income tax with rates from 2% to 5.75%, but the effective rate is higher because Maryland also imposes county income taxes ranging from 2.25% to 3.2% depending on the county. This means the total state + county individual income tax rate can reach nearly 9%. The corporate income tax rate is 8.25%, one of the higher rates nationally.
Maryland's sales tax rate is 6%, uniform statewide with no local additions. This simplifies compliance. The economic nexus threshold for remote sellers is $100,000 in sales or 200 transactions. Maryland has expanded its sales tax base to include certain digital goods and services.
Maryland requires all businesses to file an Annual Report and Personal Property Return with the State Department of Assessments and Taxation (SDAT) by April 15. This is different from most states where the annual report goes to the Secretary of State. Failure to file can result in forfeiture of your good standing. Maryland offers an elective Pass-Through Entity Tax (Form 511) allowing S-corps and partnerships to pay income tax at the entity level.
What Happens If You Miss a Maryland Tax Deadline?
Comptroller of Maryland
Get Your Books Ready Before Tax Season
Maryland's county income tax means your effective rate depends on where you live — and the combined rates can be steep. Clean books ensure accurate filing for both state and county obligations.
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