Dalila and William Timal look like any other couple signing a home mortgage. They've picked out paint colors for their new four-bedroom house in Indianapolis and can't wait for their 18-month-old son to play in the yard. But they differ in one way from many others you'd see at a loan officer's desk: Neither is a U.S. citizen or legal resident. The Timals came to this country from Guatemala in the late '90s and illegally overstayed their visas. They're the beneficiaries of a new program by Cincinnati-based Fifth Third Bank, basing mortgages on an individual taxpayer identification number or ITIN.

Nationwide, increasing numbers of financial institutions offer such loans. They view customers like the Timals as part of their communities, not to mention a critical business opportunity. Just among the nation's roughly 6 million undocumented Latinos is a potential $44 billion market for homes, according to the National Association of Hispanic Real Estate Professionals. "People need somewhere to live," said Ann Baddour, senior policy analyst with Texas Appleseed in Austin, a nonprofit group that uses volunteer professionals to solve social problems. "It's not new that people are buying homes; what's new is that banks are financing it." The Timals saved up a $3,000 down payment for their loan. "We've been working so hard to have the money ready," Dalila Timal said in an interview.

A person requests an ITIN from the Internal Revenue Service if he or she isn't eligible for a Social Security number, but must file a tax return. And while groups opposed to illegal immigration have pressured the IRS to work with immigration officials, experts say U.S. Immigration and Customs Enforcement concentrates on deporting violent criminals and people suspected of terrorist connections. Find out how to establish a credit history, get a credit card and even a mortgage in the United States (regardless of immigration status) The growth of ITIN mortgage programs is an example of how day-to-day life in America has adapted to the reality of as many as 10 million undocumented immigrants. The IRS accepts their tax payments, employers recruit them, and companies seek them out as customers.