The Oklahoma Corporation Commission reminds residential and business phone customers served by the 405 area code to prepare for the introduction of the new 572 area code.

The 572 area code will be added as an overlay to the 405 region to ensure a continuing supply of telephone numbers for the area. An overlay is the addition of another area code to the same geographic region served by an existing area code.

The overlay does not require customers to change their existing area code, but new telephone lines or services will be assigned the new 572 area code beginning May 24, 2021.

A six-month permissive dialing period will begin Oct. 24 to give customers time to adapt to the eventual requirement to dial the area code plus the number for all local calls.

Beginning April 24, 10 digits will be required for local calls in the 405 area code, but until then, local calls can be made with either seven or 10 digits. All calls that are local will continue to be local even when 10 digits are dialed.

The most important facts for customers to know about the upcoming 405/572 area code overlay are:

• Your current telephone number, including current area code, will not change.

• If you seek new phone service after May 24, 2021, you may be assigned a phone number with the 572 area code.

• You will need to dial area code plus telephone number for all local calls, beginning April 24.

• You will continue to dial 1 plus area code plus telephone number for all long-distance calls.

• What is a local call now will remain a local call.

• The price of a call, coverage area or other rates and services will not change due to the overlay.

• You can still dial just three digits to reach 911. You can also dial three digits to reach 211 and 811, as well as 311 and 511, where available.

Phone customers are reminded to include the area code when sharing their number with friends, family, business associates and others.

Customers also are advised to ensure all services, automatic dialing equipment, applications, software, or other types of equipment recognize the new 572 area code as a valid area code.

Examples include life-safety systems, fax machines, alarm and security systems, gates, ankle monitors, speed dialers, mobile phone contact lists, call forwarding settings, voicemail services, and similar functions.

Be sure to check your business stationery, advertising materials, personal checks, and your personal or pet ID tags to ensure the area code is included in your telephone number.

Important safety and security equipment, such as medical alert devices, alarm and security systems must be programmed to use 10-digit dialing. Many systems operate on 10-digit dialing by default, but some older equipment may still use 7 digits.

Please contact your medical alert or security provider if you are not sure whether your equipment needs to be reprogrammed to accommodate the upcoming change to 10-digit local dialing. Any needed reprogramming of alarm and home security equipment should be done between Oct. 24, 2020, and April 24, 2021.