The groundwork for the trend was laid in 1996, when the U.S. Treasury created Individual Tax Identification Numbers to collect taxes from workers in the United States who don't qualify for Social Security numbers.

Now, local realtors, bankers and mortgage brokers say hundreds of homes have been financed in metro Atlanta for people with federal tax ID numbers. And they expect that number to continue to rise even though interest rates on such loans are often 3 to 4 percentage points higher than average home loans.

"The last two years have seen a big increase in this type of loan," said Johnny Gonzalez, a real estate agent with Private Realty Group, with offices in Buford and Gainesville. "About 25 percent of my clients are using it, and it's growing more and more. People are asking why they should rent when they can own a house."

The next few years will see more and more immigrants doing exactly that, said Ismael Cordero, chief operating officer of the Latin American Association. It takes about a decade for immigrants to buy a house in their host country. The big wave for Hispanics into Atlanta was right before the Olympics, "so there's a big market for first-time home buyers."

And because there's such a low default rate on tax ID mortgage loans, Cordero predicts that soon the big banks will enter the market. With more competition, interest rates will fall.

For immigrants, the first step is obtaining the tax ID number. Through the end of last year, the IRS had issued about 7 million numbers, all of which begin with 9. Undocumented residents have used the numbers to pay taxes and, in some states, as a means of identification to open a bank account, apply for health insurance or obtain a driver's license.

In Georgia, many start at a Spanish-speaking business center, such as Fuerza Latina on Buford Highway, one of several Hispanic centers in metro Atlanta. Customers can get cellphones, car insurance, legal representation or tax ID numbers, among other things.

Paulo Andres Cardona, who runs the Buford Highway center, says his business is helping 50 people a week apply for the numbers. Those who are approved may use the number to open a bank account or apply for a mortgage, he said.

One group originating tax ID loans is the 10-year-old Phoenix Global Mortgage Corp. Phoenix president is Ignacio Taboada, honorary vice-consul of Spain in Atlanta.

"We have these people, they're here, they're building lives and we want to get them in the mainstream," says Phoenix underwriter Eileen Armistead. "This product allows people who've been here for 10 to 15 years, who have children here, who are making money, to own their own homes."

Abaco Mortgage, a mortgage broker in Sandy Springs, also originates tax ID mortgages, said president Benjamin Rincon. Both Abaco and Phoenix work with United Americas Bank, which has been making tax ID loans for four years. Another financial institution, Banco de Nuestra Comunidad, started making the loans in February of this year.

Interest rates on tax ID mortgages range from 4.65, with a 30 percent down payment, to the far more common 7.5 percent to 9.5 percent, for smaller down payments. Officials said several factors justify the higher rates on such loans.

The applicants, most of whom are undocumented, have uncertain immigration status and could leave the country unexpectedly, said Guillermo Zuniga, head of compliance and community outreach for Banco de Nuestra Comunidad. They also do not have credit histories, which means the risk to the bank is higher, he said.

Right now, the consumers don't pay mortgage insurance, which further increases risk to the banks. But United Americas Bank is in negotiation to obtain mortgage insurance, which will drop the interest rate by at least 1 percent, said Phoenix Global's Armistead.

Lenders also cannot sell these mortgages on the secondary market, which is a common practice among mortgage lenders. Since they can't be sold, they remain a part of a bank's portfolio, said Banco Mortgage's Rincon. A tax ID mortgage is a relatively new product, "and it has to be proven whether it's going to work out or not."

So far, bankers say they are seeing a relatively low rate of foreclosure. Since February, Banco de Nuestra Comunidad --- which has nine branches in the metro area --- has made 125 tax ID mortgage loans, valued at $16 million. Not one has foreclosed, says Luz Urretia, the bank's president and chief operating officer.

United Americas Bank president Jorge Forment is seeing the same rate of success. His bank has made 350 tax ID loans totaling $46 million to Hispanic customers since 1999. Only three have ended in foreclosure, a fact confirmed by the Georgia Superior Court Clerk's Cooperative Authority.

"Our customers are trying to do the right thing by paying their taxes," Forment says. "Unfortunately, they can't resolve the immigration issue. But they're doing the right thing to the best point they can."

United Americas Bank requires loan applicants to provide two years of filed income tax records as well as their tax ID number. Applicants must have available at least a 5 percent down payment. Officials verify all the documentation before granting the loan.

Banco de Nuestra Comunidad asks those applying for the tax ID mortgages to document two years of work history and payment history, plus one year of rent history. Banco de Nuestra Comunidid doesn't verify tax records.

"My concern would be, if these loans are not available, would they be able to purchase a home? Right now, probably not," said Duluth resident Bill Roa, chairman of the Hispanic Contractors Association of Georgia. "They're buying a piece of America, they're buying into the system, with taxes that will help pay for public schools and public services."

"A few years ago, applicants at United Americas Bank needed to have a 20 percent down payment ready, says longtime Re/Max real estate agent Jorge Garibaldi. The interest rate on the loan was then 12 percent to 14 percent.

"It was pretty expensive when it started, and since most immigrants arrive here with nothing, almost no one was getting a mortgage this way," said Garibaldi, who is based in Duluth. "Today, about 35 [percent] to 40 percent of my clients are using a tax identification number."

The growing trend of undocumented residents buying houses alarms Marietta resident D.A. King, whose American Resistance Foundation favors stricter immigration policies. He sees the practice as a troubling, unintended use for Individual Tax Identification Numbers.

King has filed complaints with various federal agencies, including the Comptroller of the Currency and the IRS, and with elected officials in Washington. He is protesting the fact that Atlanta banks are giving mortgages to undocumented residents.

"It's my contention that people are profiteering from the presence of illegal aliens in this country, and I regard illegal immigration as organized crime," King says.

Aware that people were using the document as a form of personal identification, IRS commissioners in February tightened the procedure for obtaining an Individual Tax Identification Number.

Now, applicants must file a tax return along with a new federal form, must provide identification documents and must prove the number will be used to file taxes. Those people qualifying now receive a letter of confirmation, not a card resembling a Social Security card.

That remains enough for bankers like Urretia of Banco de Nuestra Comunidad.