What this notice is about Important Information about your child's Adoption Taxpayer Identification Number (ATIN). We assigned your child an ATIN. What you need to do Complete Form 15101, Provide Social Security Number (SSN) for Adoptive Child PDF, included with your notice when you receive a Social Security number (SSN) for your child. Detach notice stub, mail it with Form 15101 in the envelope provided. If you prefer, you can fax it to the fax number in the notice using a fax machine or an online fax service. Several online fax services use the internet to send files form your computer or smart device to a fax number. You may want to Call us at the number listed in your notice. See additional information on Adoption Taxpayer Identification Number. Frequently asked questions How long is an ATIN useful? An ATIN is valid for 2 years. If you don't have an SSN for your child, you can request a 1 year extension. For more information, see instructions for completing a Form W-7 A, Application for IRS Adoptions for IRS Individual Taxpayer Identification Number. Reference Tools Publication 1, Your Rights as a Taxpayer Full list of tax forms and instructions Bezwen èd? Ou ka otorize yon lòt moun nan (an anglè) pou kontakte IRS pou ou. Gade si w kalifye pou jwenn èd soti Klinik pou kontribyab ki gen fèb revni (an anglè). Si w pa kapab jwenn sa w vle a anliy, rele nan nimewo IRS nan pati anlè notifikasyon oswa lèt ou a.