Does anyone have sample letters to the IRS for different situations? Maybe one with code numbers and explainations.Letter 6419 includes: Number of qualifying children used to calculate advance payments, and repayment protection when filing your 2021 federal tax return. This publication discusses some tax rules that affect every person who may have to file a federal income tax return. An individual claimed as a dependent must be a citizen, national, or resident of the United States, or a resident of Canada or Mexico. To quickly search for a notice or letter on this page, you can press Ctrl-F in most browsers and type in the number or name, then press Enter. Proof of U.S. residency for applicants who are dependents. You can find the CP or LTR number on the right corner of the letter. You may be able to claim the child for the Credit for Qualifying Older Children. If you received either of those, you will need these forms to file your 2021 income tax returns don't throw them out!