How Maryland sales tax deadlines work.
Maryland sales and use tax returns are generally due on the 20th day of the month following the reporting period. New accounts are commonly assigned quarterly filing at first, but the Comptroller may assign monthly, quarterly, semiannual, or annual filing based on the account.
| Filing frequency | Standard timing |
|---|---|
| Monthly | 20th day of the month after the reporting month. |
| Quarterly | 20th day of the month after the calendar quarter. |
| Semiannual / annual | 20th day of the month after the assigned reporting period. |
Build the client workflow before the due date.
The legal deadline is the last step. Set an earlier request date for source reports, then reserve time for reconciliation, exception review, return preparation, approval, and payment. Each obligation should identify the client, state account, reporting period, assigned frequency, preparer, reviewer, and payment owner.
Account schedule
Confirm registration, filing frequency, period, portal access, and special payment requirements.
Filing packet
Reconcile gross and taxable sales, exemptions, marketplace activity, refunds, and tax collected.
Proof of completion
Keep the reviewed return, filing confirmation, payment evidence, and notes together.
Maryland client checklist.
- Verify the assigned frequency in the official state account.
- Confirm the reporting period and any weekend or holiday adjustment.
- Set internal report, preparation, review, approval, and payment dates.
- Track zero-return, amended-return, and notice-related work separately.
- Reconcile direct sales, marketplace sales, deductions, refunds, and tax collected.
- Save return and payment confirmations with the completed period.
Official Maryland sources.
This page was reviewed September 25, 2026 using the Comptroller of Maryland Business Tax Tip 22 and Maryland sales and use tax resources. State guidance and account assignments can change. Verify the client's current portal instructions before filing or paying.
Connect research to the firm calendar.
Use the AtomicTax multi-client tax calendar to turn the verified state date into accountable work. For registration, nexus, and broader state requirements, read the Maryland filing guide or browse the state resource directory.