St. Lawrence County residents will need to dial 10 digits to make a phone call beginning Feb. 11.

The new area code overlay will require nearly all St. Lawrence County residents to dial 315 or 680 when making local calls.

Actual phone numbers for people with 315 area codes won’t change, but new phone numbers in the area will be assigned with 680 area code.

Nearly all of St. Lawrence County is in the 315 area, however a small part in the southeast of the county is in the 518 area. The 518 portion of the county will not be affected by the changes.

Beginning Feb. 11, the new calling procedure will be required for all calls. On or after this date, failure to use 10 digits will result in uncompleted calls. If a person fails to dial 10 digits a recording will instruct the caller to hang up and dial again.

Beginning March 11, new telephone lines or services may be assigned numbers with the 680 area code. Those with a 680 area code, must enter the area code and seven-digit phone number on all calls or the call won't be completed.

Anyone with automatic dialing will need to ensure those numbers include the area code as well or they will no longer work.

Pet owners are reminded to include the area code on tags.

Other items that may need to be changed include security and fire alarm systems, security gates, call forward settings, fax machines, internet dial-up numbers and voicemail services.

More information on the overlay plan can be found at www.dps.ny.gov.