Nearly 2 million taxpayer households will be impacted by expiring ITINs this year, according to the IRS.

Any ITIN, a tax ID number used by taxpayers who don’t qualify to get a Social Security number, with middle digits 83, 84, 85, 86 or 87 will expire at the end of this year. In addition, any ITIN not used on a tax return in the past three years will expire. ITINs with middle digits 70 through 82 that expired in 2016, 2017 or 2018 can also be renewed.

Affected taxpayers should file a renewal application, Form W-7, “Application for IRS Individual Taxpayer Identification Number.” They should be sure to include all required ID and residency documents.

Common application errors generally center on missing information or insufficient supporting documentation. A reason for needing the ITIN must also be selected on the W-7.

Spouses and dependents residing outside the U.S. who would’ve been claimed for a personal exemption should not renew their ITINs this year unless they are filing their own tax return or they qualify for an allowable tax benefit.

More information is on the ITIN information page on IRS.gov.