Follow the steps to successfully complete the DC D-40B form online.

1. Press the ‘Get Form’ button to access the DC D-40B form and open it in your preferred editor.
2. Begin by entering your personal information in the designated fields, including your first name, middle initial (if applicable), last name, Taxpayer Identification Number (TIN), date of birth, daytime phone number, and current mailing address.
3. Review categories A and B regarding exemptions. Indicate your situation by entering the two-letter state abbreviation for your domiciliary state of residency if applicable, and ensure you attach any necessary withholding statements, including DD Form 2058 if you are claiming the military spouse exemption.
4. In the 'Refund request' section, round your amounts to the nearest dollar. Enter the total DC income tax withheld and your estimated income tax payments in the appropriate fields, then sum these amounts for the total refund request.
5. Select your preferred refund option: direct deposit, ReliaCard, or paper check. If choosing direct deposit, fill in your account type and provide your bank routing number and account number.
6. Designate a third-party individual to discuss your return with the appropriate authorities, if desired, by filling in their name and phone number.
7. Review your application and confirm that all provided information is correct. Sign and date the form, and include the preparer's signature and Tax Identification Number if applicable.
8. After completing all sections, you can choose to save changes, download, print, or share the form as necessary.

Complete your DC D-40B form online today to ensure timely processing of your refund.