Understanding the difference between an SSN and ITIN is key to filing taxes correctly and avoiding mistakes that can delay your benefits.

The Individual Taxpayer Identification Number (ITIN) may be the key you need to open that elusive credit card door.

Individual taxpayer identification number (ITIN). If you (or your dependent) does not qualify for an SSN, you may be able to apply for an individual taxpayer identification number (ITIN).

An ITIN can be obtained by filing an IRS Form W-7, but the process is cumbersome, often requiring original copies of documents, such as passports, that the applicant may not want to part with.

Without a Social Security number, you can sometimes apply for a credit card using your Individual Taxpayer Identification Number (ITIN).