504UP: Underpayment of Fiduciary Income Tax (2025)
Maryland · Comptroller of Maryland · Used for tax years 2025
Maryland Form 504UP calculates an estate’s or trust’s underpayment of estimated income tax and any interest due for 2025. It includes calculations for required payments, underpayments by installment period, and the annualized income installment method, and is attached to Form 504
Who files this form
Complete Form 504UP and submit it with your fiduciary tax return if you believe you owe interest for failing to file or pay estimated tax on time, or for underestimating the required tax.
You do not need to file this form if any of these exceptions applies:
- The tax year ends less than two years after the decedent’s date of death.
- Tax liability on gross income, after subtracting Maryland withholding, is $500 or less.
- Each required quarterly payment is at least one-fourth of 110% of last year’s tax.
You may also let Maryland calculate the interest. Complete your return as usual without Form 504UP, and you will be notified of any interest due.
If you use the annualized income installment method, attach Form 504UP and enter code 301 on Form 504, even if no interest is due.
When it's due
The form lists these estimated tax installment due dates for tax year 2025:
- April 15, 2025
- June 15, 2025
- September 15, 2025
- January 15, 2026
Submit Form 504UP with Form 504 when required. The supplied text does not state a separate filing deadline for Form 504UP.
What you'll need
Have these forms and records available, as applicable:
- 2025 Form 504, for income, tax, and credit amounts.
- Form 504NR, if you are a nonresident fiduciary required to use Part II.
- 2024 Form 504, including any additional tax from corrections or amendments.
- Records of estimated tax payments and Maryland tax withheld for each period, including payment dates.
- Form 502TP, if you have tax preference items.
- The estate or trust’s name and Federal Employer Identification Number.
For the annualized income installment method, you also need income amounts for the periods shown on page 2 and the tax rate schedules in the Form 504 instructions.
How to file
Attach Form 504UP to your 2025 Form 504 and submit it with your fiduciary return. The supplied text does not provide a mailing address or e-filing instructions.
- Complete lines 1 through 9 to determine the minimum required withholding and estimated tax.
- Complete lines 10 through 12 to calculate underpayments.
- Complete lines 13 through 15 to calculate interest.
- If using the annualized income installment method, complete lines 16 through 32 and enter code 301 on one of the Code Number lines at the bottom of Form 504.
Include the interest in your total payment with the return. The supplied text has conflicting transfer instructions: the form’s line 15 says to enter interest on Form 504, line 39, while the included instructions say line 38.
Common mistakes
- Leaving out corrected prior-year tax. When completing line 8a, include additional 2024 tax from a correction or amendment.
- Using only the current period’s payments on line 11. Each successive column must include payments and withholding from the earlier columns.
- Completing annualization rows across the page first. Complete lines 16 through 32 in one column before starting the next column. Income amounts on line 16 are cumulative.
- Using annualization for only some installments. If you use this method for one payment due date, you must use it for all payment due dates.
- Omitting the form or code 301. Both are required when using annualization, even if no interest is due. Also attach the form and enter code 301 if you complete it and owe no interest because of the distribution of income.
Questions people ask
Can Maryland calculate the interest for me?
Yes. Complete your return as usual and do not file Form 504UP. You will be notified of any interest due.
What if the estate or trust’s income varied during the year?
The annualized income installment method may lower or eliminate one or more required installments. If you use it for any payment due date, you must use it for all payment due dates.
What amount does a first-time filer enter on line 9?
A first-time filer enters the amount from line 7, rather than comparing it with the prior-year tax calculation on line 8b.
What exemption is used in the annualized calculation?
On line 19, personal representatives of a decedent’s estate enter $600. All other fiduciaries enter $200.