The 405 area code covering central Oklahoma might have a companion area code earlier than forecast after an unexpected surge in telephone number requests last year.
The North American Numbering Plan Administration's latest forecast shows numbers could be exhausted in the 405 area code by 2016, four years earlier than its forecast from April 2012.
Oklahoma has four area codes, with 405 serving central Oklahoma and 580 covering western and southern Oklahoma. The Tulsa area and most of eastern Oklahoma are served by 918 and 539, a new overlay area code added in 2011. Customers in 918 and 539 have to dial 10 digits for local calls.
The forecast is important because relief planning for new area codes should begin 36 months before an expected date of exhaustion, said Joe Cocke, a senior relief planner with the North American Number Plan Administration. The group works with regulators and telecom companies to assign area codes and prefixes.
Cocke said a new forecast should be out by the end of April. Recent indicators show number demand slowing in the 405 area code, so the forecast could be pushed back to a later date.
“As we've been watching this area code, the demand has dropped off since September,” Cocke said. “We're monitoring it. We've got a unit that's analyzing all the forecasted data that's coming in from service providers on what they project their needs are going to be.”
Cocke said there are about 800 usable three-digit prefixes for each area code. Prefixes beginning with a one or zero aren't used, and some prefixes are for testing purposes. Others, such as 555-, are partly reserved for fictitious use in television or film.
Just 117 prefixes remain for the 405 area code, less than 15 percent of the available three-digit prefixes, he said.
Regulatory officials said the spike in demand for telephone numbers in the 405 area code could be traced to an influx of new customers in the federal Lifeline program, which provides subsidized landline or wireless service to low-income households. Money for the program comes from Universal Service Fund fees tacked on to most telephone customer bills.