https://www.irs.gov/pub/irs-pdf/iw7.pdf

Filing Taxes Without a Social Security Number

The 2020 Form 1040 requires that a taxpayer enter their Social Security number (SSN) at the top of the tax return. This obviously poses a problem for undocumented workers who are required to file returns but are seemingly prohibited from doing so because they aren’t eligible for SSNs.  

Some noncitizens can apply for and receive Social Security numbers, however. Noncitizens might be temporarily authorized to work through Deferred Action for Childhood Arrivals (DACA)2 or temporary protected status (TPS).3

Noncitizens might also have access to work visas. 

These SSNs are only valid for a limited authorized time, but this technically means the noncitizens are not “undocumented.” 

What Are Individual Taxpayer Identification Numbers?

Undocumented workers have another option: the Individual Taxpayer Identification Number (ITIN). An ITIN can be used in place of an SSN. The IRS created the it back in 1996 to encourage those ineligible for an SSN to file returns and pay taxes.4

An ITIN is not an authorization to work in the United States, however. Receiving one doesn’t mean that you’re a documented alien or resident. It simply allows you to file a tax return and pay taxes.