If your income varied during the year because, for example, you operated your business on a seasonal basis, you may be able to lower or eliminate the amount of one or more required installments by using the annualized income installment method.
If you use Schedule A for any payment due date, you must use it for all payment due dates. To figure the amount of each required installment, Schedule A automatically selects the smaller of the annualized income installment or the regular installment (increased by the amount saved by using the annualized income installment method in figuring earlier installments).
For more information see instructions for form N210
