ALBANY — The state Public Service Commission has announced the phase-in of a new 838 area code for residential, business and wireless customers within the existing 518 area code.

To ensure a continuing supply of telephone numbers, the commission in 2016 approved the 838 area code to be “overlaid” across the 17 counties that make up the 518 area code, including Essex and Franklin counties.

The phase-in starts March 18 with what the commission calls a “permissive dialing phase,” when customers will be able to dial either seven or ten digits on calls within the 518 area code. The permissive period will end on Aug. 19, when all callers in the region will be required to dial ten digits each time they make a call.

No current telephone numbers, including those with a current 518 area code, will change. Calls to reach 911 emergency services will not change.

“Customers should identify their telephone number as a 10-digit number (area code + 7-digit local telephone number) when giving the number to friends, family, business associates and business customers,” the commission said in a press release.

It also advised customers to ensure that any automatic dialing equipment, applications or software like life safety systems, fax machines, alarm systems and call forwarding systems recognize the new 838 area code as a valid area code.

“All calls within the 518/838 area must be programmed to dial using 10-digits and the digit prefix ‘1’ must be included for all calls to other area codes,” the release states.

In addition to Essex and Franklin counties, the change also applies to Albany, Clinton, Columbia, Dutchess, Fulton, Greene, Hamilton, Montgomery, Rensselaer, St. Lawrence, Saratoga, Schenectady, Schoharie, Warren and Washington counties.

The Associated Press contributed to this report.