Follow the steps to complete the NY IT-638 form online.

1. Press the ‘Get Form’ button to acquire the form and open it in the editor.
2. Begin by marking whether you are a calendar-year filer by checking the appropriate box. If you are not a calendar-year filer, enter the tax period's starting and ending dates.
3. Fill in the names as they appear on your tax return and provide your identifying number as shown on the return.
4. Complete line A, indicating whether you are claiming the credit as an individual, partnership, or fiduciary. Mark the appropriate box.
5. If you answered 'Yes' to line A, continue to complete lines B, C, and D. If 'No,' continue to complete lines B, C, and D and Schedules B, D, and E.
6. For line B, input the certificate number from Form DTF-74 that was issued to your approved Start-Up NY business.
7. For line C, indicate if you are certified by multiple sponsors by marking the corresponding box and listing the sponsor names in the provided space.
8. On line D, enter the year of the Start-Up NY business tax benefit period, choosing a number from 1 to 10 as instructed.
9. Proceed to Schedule A, where you will complete the allocation factor section, entering values as per the provided instructions.
10. Once all relevant information has been filled in, you can save changes to the completed form. You also have options to download, print, or share the form as needed.

Complete your NY IT-638 form online today for efficient tax credit application.