What this notice is about We have important information about your child's Adoption Taxpayer Identification Number (ATIN). Your child's ATIN expires in 3 months. What you need to do Complete Form 15100, Adoption Taxpayer Identification Number (ATIN) PDF Extension Request, included with your notice if you received a Social Security number (SSN) for your child, or; Apply for a one-year extension of this ATIN by completing Form 15100, if you don't have an SSN. Detach notice stub, mail it with Form 15100 in the envelope provided. If you prefer, fax your information to the fax number in the notice using either a fax machine or an online fax service. Protect yourself when sending digital data by understanding the fax service’s privacy and security policies. You may want to Call us at the number listed in your notice. See additional information on Adoption Taxpayer Identification Number. Frequently asked questions What can I do if I don't have a Social Security number (SSN) for my adoptive child? You can request an extension before your assigned ATIN expires by completing Form 15100 included with your notice. The extension is only valid for 1 additional year. Reference tools Publication 1, Your Rights as a Taxpayer Full list of tax forms and instructions 是否需要帮助？ 您可以授权他人（英文）代表您联系国税局。 查看一下您是否有资格获得低收入纳税人诊所的帮助（英文）。 倘若您在网上未能找到所需信息，请拨打通知或信函顶部的国税局电话号码。倘若您未收到信函或通知，请使用电话协助。 如果您不能自行解决罚款问题，请联系纳税人权益服务处，这是国税局内部的一个独立机构。
