8288-B withholding certificate timing and procedure. 20 days versus 90+ days
In certain cases, you may use Form 8288-B to apply for a withholding certificate. The IRS will normally act on an application by the 90th day after a complete application is received.
If you receive a withholding certificate from the IRS that excuses withholding, you are not required to file Form 8288.
However, if you receive a withholding certificate that reduces (rather than eliminates) withholding, there is no exception to withholding, and you are required to file Form 8288. Attach a copy of the withholding certificate to Form 8288.
A buyer must file Form 8288 and transmit the tax withheld to the IRS by the 20th day after the date of transfer. Buyer must withhold (not the same as actually remitting to IRS) even if an application for a withholding certificate is or has been submitted to the IRS on the date of transfer. However, buyer does not have to file Form 8288 and transmit the withholding until the 20th day after the day the IRS mails you a copy of the withholding certificate or notice of denial.