Mortgage lenders say homebuyers hoping to claim a federal tax credit had better get a move on.

People who haven't owned a house in the past three years may be eligible for an up-to-$8,000 federal tax credit on a home purchase, thanks to a provision in the economic stimulus package passed in February. But that part of the law is set to expire on Nov. 30, and lenders are telling buyers they need to get their paperwork done well before that date to cash in.

"We need a full and complete application to be delivered to our underwriting teams no later than Oct. 30," said Amy Savicky-Injaian, a spokeswoman for banking giant Wells Fargo & Company.

Other lenders want paperwork in even sooner, in case of snags along the way.

Real estate brokers have seen a flurry of activity this summer among new buyers looking to take advantage of discounted house prices and low interest rates on loans.

In July, August and September, 28 percent of San Diego County and 48 percent of Riverside County home purchases were insured by the Federal Housing Administration, according to MDA DataQuick, and these loans typically go to first-time homebuyers.

But real estate agents say the tax incentive inflated the percentages because it nudged uncertain potential homebuyers into the market. Now those same buyers are frantically trying to close on their houses by the November deadline, which means getting their loan applications in by the end of October.

"We are definitely seeing an uptick in the last month," said Linda Harbert, a branch manager for Coldwell Banker in Rancho Bernardo.

Oraisa Ingle and her partner, Shindana Perryman, are in the thick of the buying scrum. The couple care for Perryman's brother, who has Down syndrome, and two foster children. They didn't decide to expand their living space until this summer. The tax credit pushed them over the edge.

"It's huge for us; it would help us out a lot," Ingle said.

Now they're trying to get qualified for a loan and find a place they like in the few weeks they have left, but are also holding out hope the provision will be extended.

Lobbyists for Realtors, mortgage bankers and others who benefit from a strong housing market have been leaning on Congress to extend the law. Several bills have been introduced in Congress, says Diane Conaway, an Escondido-based Realtor who tracks legislation for the California Association of Realtors.

"We want to see which one is going to win out," she said. "One would extend it for six months, another for a year; another would make it not just first-time buyers."

Call staff writer Eric Wolff at 760-740-5412.