The Internal Revenue Service has issued some taxpayers an essential letter that could be critical for filing their 2021 tax return. Continue reading to find out why you need Letter 6419.

Letter 6419 is a one-page black-and-white letter with an IRS emblem in the upper left corner. It is issued by the Treasury Department and the IRS.

According to the IRS, taxpayers must use Letter 6419 when filing their 2021 tax return to match the advanced payments they received last year with the remaining child tax credit they are owed and can claim on their return.

"Advance Child Tax Credit payments are early payments from the IRS of 50 percent of the estimated amount of the Child Tax Credit that you may properly claim on your 2021 tax return during the 2022 tax filing season," the IRS explains on its website.

Letter 6419 contains crucial information that will assist you in preparing your taxes. The notice will detail the amount of child tax credit money you got in 2021, as well as the number of qualified dependents that were utilized to compute your total amount.

You should double-check the information to ensure that it is still correct. For example, if you had a child since your last tax return, the IRS would not have taken that into account when calculating how much money you're entitled to. As a result, when you file your tax return, you'll need to make sure your information is up to current.

Don't get too worked up if you misplace it or lose it. Your child tax credit information will be available on the IRS website's child tax credit portals.

It takes some time and patience to register for an account on the IRS website, but once you're in, you'll have all the information you need for the child tax credit, as well as other helpful IRS information for completing your taxes.

The amount of child tax credit money you receive with your tax refund is determined by several factors. For example, if you opted out of getting monthly payments last year, the amount of money you receive will be greater than if you received every check. Monthly payments of up to $300 were made to children aged 5 and under, and up to $250 to children aged 6 and beyond.

If you were qualified for the entire amount and chose not to make payments, your tax refund could be up to $3,600 per child. However, depending on your children's ages, you may receive up to $1,800 per child if you got all six payments in 2021.

If you haven't received a letter before the deadline for filing your return, you can either utilize the online child tax credit portals to double-check your information or contact the IRS directly by mail or phone at 1-800-829-1040. Expect to wait at least 30 days for a response if you contact the IRS via mail.