Starting Sunday, Michigan telephone customers in 616, 810, 906 and 989 area codes will have to switch to 10-digit dialing.
That means phone customers including landline and mobile phones in those area codes must include the area code with every local call.
If you don’t include the area code, your call will not be completed. Instead, you’ll get a recording informing you that your call cannot be completed as dialed.
Sunday marks the end of the permissive dialing period that started in April and allowed calls dialed with either 7 digits or 10 digits.
RELATED: TDS Telecom customers in area code 616 will soon be required to dial 10-digit numbers for local calls
Customers in other area codes in Michigan will not be affected by these changes.
The 10-digit dialing requirement is in preparation for the rollout of the National Suicide Prevention Lifeline in 2022.
Safety and security equipment like medical alert devices and security systems will need to be programmed to use 10-digit dialing by October 24.
Here’s a list of other services that may need to be reprogrammed before Sunday:
• life safety systems or medical monitoring devices
• PBX business telephone systems
• fax machines
• internet dial-up numbers
• fire or burglar alarm and security systems or gates
• speed dialers
• mobile or other wireless phone contact lists
• call forwarding settings, and
• voicemail services and other similar functions.