What is a tax ID number? When you are filing your taxes, you need a Taxpayer Identification Number (TIN) that will put you on the tax-paying map. Only when you have a tax ID, the IRS won’t recognize you. Without this TIN, which is also known as a tax ID number, the IRS won’t know who you are, or how much tax you owe the IRS. You won’t be able to talk to them either.

A Tax Identification Number or TIN is a sequence of 9 numbers you are allotted the first time you pay your tax money. The IRS identifies you with the help of this number. Your Social Security Number is usually used as your tax ID number. But there are four other types of tax ID numbers, namely: the ITIN, EIN, ATIN, and PTIN.

Individual Taxpayer Identification Number (ITIN)

What is ITIN

This individual taxpayer identification number consists of 9 digits. This type of identification number is given to those who are non-residents and resident aliens of the United States of America. Resident and non-resident aliens are those who live in America but whose birthplace isn’t America. This ITIN number is also given to those who are married to these non-resident and resident aliens and their dependents. The reason why this number is provided to this group of people is that they cannot get a Social Security Number.

How to get an ITIN

If you want to receive an ITIN in order to pay your taxes, you will have to fill out an IRS Form W-7. You will have to provide documents that prove your foreign/alien identity and status. Furthermore, you will also need to provide a federal tax return for your W-7 Form. If you don’t know how to get an ITIN, there are many organizations called “acceptance agents” who have IRS authorization. These can help you get your ITIN. 



If you didn’t use your ITIN number to file for taxes even once during the years 2018, 2019, or 2022, then your ITIN number would have expired by the end of 2021. Some ITINs with middle numbers 70 to 88 and 90 to 99 have also expired. It’s important to note that only those ITINs that were assigned before 2013 have expired. 

Employer Identification Number (EIN)

What is EIN

An EIN is for those who are employers and run businesses or partnerships. With the help of this Employer Identification Number, the employer will withhold the employee’s taxes from their income/salary. This is also for non-resident aliens. This number is also used to file tax returns in certain organizations that have to do anything with tobacco, alcohol, and firearms. Your businesses must strictly limit to the United States territory and you need to own a Social Security Number, ITIN, or other EIN. 

How to get an EIN

You can apply for an EIN online. The IRS will receive your application and will reach out to you for further queries. You can also fill out the IRS Form SS-4 and mail this to the IRS. You can also fax them if you want. If you aren’t in America but you’re moving there soon and need an EIN, then you can call them on 1-267-941-1099. This number is only for international applicants.


If you run a business, then that business needs a separate employer ID number.

Adoption Taxpayer Identification Number (ATIN) 

What is ATIN

This identification number is a 9-digit tax ID number that is given to those who are in the process of adopting a child. It is important to note that this is just a temporary identification number for those couples and parents who cannot get a Social Security Number. This number isn’t for the parents but is given to the child by the IRS who is a dependent to their adopted parents. 

How to get an ATIN

To apply for an ATIN, you will have to fill out an IRS Form W-7A. You will have to provide all the documents related to child adoption and placement. When you are applying for this ATIN, the child must be residing in your home. On the other hand, if you are adopting a baby from a different country altogether, the rules differ and there are different sets of requirements and rules you need to follow.


Preparer Tax Identification Number (PTIN)

What is PTIN

This is for those who prepare any kind of federal tax returns and work at the IRS. If you prepare or assist in preparing tax returns to the public, you will be asked to apply for a PTIN. If you have a PTIN and prepare tax returns for your clients, then you will have to mention your PTIN number in the document. 

How to get a PTIN

You can apply for a PTIN online and you will get this in just 15 minutes. The longer method to apply for PTIN is where you have to fill out IRS Form W-12 and send it to the IRS. You will have to wait for 4 to 6 weeks to hear from them again.