The S.C. Employment Security Commission has begun taking claims for 26,000 jobless workers who have exhausted their benefits.
The agency is accepting claims for an extra 13 weeks of checks from a federally funded extension signed by President Barack Obama in November.
The commission's work force centers will stay open longer this week, including opening on Saturday, to accommodate new benefits requests.
Meanwhile, the U.S. House approved a measure Wednesday that would make sure that federal jobless benefits extensions don't expire at year's end.
With nearly 95,000 jobs shed since the recession started two years ago, more South Carolinians are unable to find work and are using up their unemployment check eligibility. South Carolina's jobless rate stands at an all-time high of 12.1 percent, fifth worst in the nation.
The commission has sent notices to 26,000 people who are potentially eligible for the extension because they have exhausted their state and federally paid benefits, said Jimmy Jones, the agency's assistant deputy executive director.
About 71,000 South Carolinians currently get federally funded unemployment extension checks because they have exhausted the first 26 weeks of checks paid by the state.
The jobless in South Carolina could get up to 79 weeks of help before the latest 20-week extension.
But checks from the latest federal extension have been delayed for a few weeks as the state agency re-programmed its 23-year-old computer system, officials said. The system has been trying to keep up with four different extensions the federal government has issued during the recession.
"This is nothing like we've ever dealt with," agency spokesman Clark Newsom said.
Other states have struggled with computer programming over the new payments, said Marc Katz, intergovernmental affairs director at the National Association of State Workforce Agencies: "You're hardly alone."
But those extra jobless checks, along with other benefits for the unemployed, are scheduled to end Dec. 31 without Congressional action.
On Wednesday, the U.S. House approved extending federal jobless benefits through February. The measure also kept $25 added on weekly unemployment checks as well as extended company medical coverage in the months after workers lose their jobs.
The Senate is expected to approve the jobless benefit extensions next week.