500UP (2D): Underpayment of Estimated Income Tax by Corporations and Pass-Through Entities (2D) (2025)
Maryland · Comptroller of Maryland · Used for tax years 2025
Maryland Form 500UP calculates interest and penalties for corporations and pass-through entities that did not pay the required estimated income tax when due. It reports required installments, payments, underpayments, and total interest and penalties, and is attached to Form 500,
Who files this form
Form 500UP is optional. Corporations and pass-through entities use it to calculate interest and penalties for not paying enough estimated Maryland income tax on time. If you do not file it, the Revenue Administration Division will calculate the charges and notify the entity of any balance due.
Estimated payments are required if the entity reasonably expects its Maryland taxable income to produce tax of more than $1,000 for the tax year or period.
The form says no interest or penalty is due, and Form 500UP should not be filed, if:
- Current-year tax is $1,000 or less.
- Four timely payments each cover at least 25% of the required estimated tax and together total either 90% of current-year tax or 110% of prior-year tax.
- The entity has a short tax period of less than four months.
When it's due
For tax year 2025, file Form 500UP, if used, by the original or extended filing due date for Form 500, 510, or 511. The filing instructions do not give a specific calendar date for attaching Form 500UP.
For calendar-year 2025 estimated payments:
- Corporations and S corporations: April 15, June 15, September 15, and December 15, 2025.
- Other pass-through entities: April 15, June 15, and September 15, 2025, with the fourth payment due January 15, 2026.
For fiscal tax years beginning in 2025, the form lists the 15th day of the fourth, sixth, ninth, and twelfth months. The instructions specify that other pass-through entities instead make their fourth payment by the 15th day of the month following the close of the tax year.
What you'll need
Have these returns and details available to complete Form 500UP:
- Your current and prior-year Maryland Form 500, 510, or 511, including the tax amounts used on Form 500UP.
- The entity's name as shown on the return and its nine-digit Federal Employer Identification Number (FEIN).
- The beginning and ending dates of the tax year.
- Applicable Business Tax Credits, Heritage Structure Rehabilitation Tax Credits, and current-year credits for tax paid on the entity's behalf by a pass-through entity.
- Estimated payment amounts and payment dates, plus any prior-year overpayment applied to estimated tax.
- Income received during each installment period, if a partnership or limited liability company elects to annualize.
How to file
- Enter the entity's name, FEIN, and tax-year dates. Use the form with the preprinted year in which the entity's tax year begins.
- Complete lines 1 through 13 using the calculation instructions. Line 6 generally uses cumulative required amounts: one-quarter, one-half, three-quarters, and the full amount from line 4. Special instructions apply to pass-through entities that annualize.
- Enter total interest and penalty from line 13 on Form 500, line 18; Form 510, line 19; or Form 511, line 16.
- Attach Form 500UP to Form 500, 510, or 511 and file it with:
Comptroller of Maryland
Revenue Administration Division
110 Carroll Street
Annapolis, Maryland 21411-0001
The supplied text does not provide e-filing instructions.
Common mistakes
- Skipping the instructions: The form specifically says to review them before completing Form 500UP.
- Treating the form as mandatory: The instructions state that Form 500UP is not required.
- Annualizing a corporation's income: Corporations may not use the annualization method.
- Using cumulative line 8 amounts to calculate the penalty: The line 12 instructions explicitly say not to use those cumulative amounts. Add the underpayments for the applicable individual quarters instead.
Questions people ask
How much estimated tax is required?
Line 4 uses the lesser of 90% of current-year tax or 110% of prior-year tax, using the tax amounts specified on the form. First-time filers use 90% of current-year tax.
What if the entity has not received its FEIN?
Enter “APPLIED FOR” followed by the application date. If the entity has not applied for a FEIN, the instructions say to do so immediately.
When does an underpayment penalty apply?
A penalty applies for any quarter when timely payments are less than 50% of one-quarter of the annual estimated tax required on line 4. Add the underpayments for all applicable quarters, without using cumulative line 8 amounts, and multiply the total by 10%.
What if a partnership or limited liability company receives income unevenly?
Partnerships and limited liability companies electing to annualize must base each period's line 6 payment amount on income received during that installment period. If line 11 interest is zero because income was not received evenly throughout the year, enter code “301” on a code-number line on the front of Form 510 or 511 and attach Form 500UP.