Where can I enter withholding from Form 8288-A?
Per the Instructions for Form 8288-A:
"You must file a U.S. tax return (Form 1040NR, 1041, 1065, 1065-B, or 1120-F) to report the sale or other disposition as effectively connected with the conduct of a trade or business in the United States. To receive credit for any federal income tax withheld shown in box 2, attach Form 8288-A to your tax return, unless you make a request for early refund."
In a 1040-NR, enter data on the Foreign tab > screen 8288 Statement of Withholding on Dispositions screen to generate and e-file Form 8288-A. Form 8288-A is generated in View/Print mode and is included with the e-filed return; it does not need to be attached separately as a PDF.
In a 1065, an entry can be made on the Foreign tab > screen 8804, line 6d.
Note: Other entries may be available. You will need to determine the correct entry as it applies to your taxpayer's return and within IRS guidelines.