INDIANAPOLIS — Callers in northern Indiana’s 219 and 574 telephone area codes will soon be required to dial with 10 digits, rather than seven, when making local phone calls.

Beginning April 24, callers in the 219 or 574 area codes should use 10 digits whenever placing local calls. Seven-digit dialing will still be completed until Oct. 24 to give people time to adjust to the new dialing pattern and make any required system changes before 10-digit dialing becomes mandatory.

But after Oct. 24, calls without 10 digits will not be completed in the two area codes.

The change to 10-digit calling is necessary to accommodate the national “988” National Suicide Prevention Lifeline, according to the Indiana Utility Regulatory Commission.

All telecommunications providers in the United States are required to implement the three-digit 9-8-8 dialing code for the hotline by July 16, 2022. Under an order issued by the Federal Communications Commission, 10-digit dialing must be in place before then for any area code with a “988” prefix.