What this notice is about If you received a CP521, CP521 (SP) or CP621 Notice, the IRS is reminding you that you have an installment payment due. Send your payment immediately. View this notice and manage your communication preference online Sign in to your Online Account to: View and download this notice Go paperless for certain notices Get email notifications for new notices What you need to do Read your notice carefully. It's a reminder to send in your monthly payment. Pay by the due date. Go to the payments page to find out more about your payment options. Frequently asked questions What is the notice telling me? Your monthly installment agreement payment is due to us by a specific date. What do I have to do? Pay the amount due shown on the notice. Mail us your payment in the envelope we sent you. Include the bottom part of the notice to make sure we correctly credit your account. What happens if I don't pay? If you don't send us a payment, the interest and penalties you'll have to pay will increase and you could default on your installment agreement. Who should I contact? If you have any questions, call us at the number at the top of the notice. A customer service representative will assist you. Reference tools Publication 1, Your Rights as a Taxpayer Full list of tax forms and instructions Bezwen èd? Ou ka otorize yon moun (an anglè) pou kontakte IRS la pou ou. Gade si w kalifye pou resevwa èd nan men yon Sant pou Kontribyab ki gen Revni Fèb (an anglè). Si w pa kapab jwenn sa w vle a anliy, rele nan nimewo IRS nan pati anlè avi oswa lèt ou a. Si w pa te resevwa yon lèt oswa yon avi, itilize asistans telefonik Si ou pa ka rezoud penalite a poukont ou, kontakte Sèvis Defans Kontribyab la, yon òganizasyon endepandan anndan IRS.
