The Lowcountry and Pee Dee areas will get a new area code, although it’s not yet known what it will be.

A plan for a new overlay area code for the 843 region was approved Wednesday by the state’s Public Service Commission.

That means people throughout the region will have to dial at least 10 digits in order to make a phone call starting around the beginning of 2015, because there will be two area codes instead of one.

No one will lose the phone number they have now because of the change. In other words, if you like your current phone number, you can keep it.

The region will get a second area code because population growth and the proliferation of cellphones are exhausting the available 843 numbers.

By the end of 2015, the supply of available 843 area code numbers is expected to run out.

The new, second area code number has not been disclosed.

Here are some questions and answers about what will happen, and why:

Q: What happens next?

A: Telephone utilities serving the 843 area will spend six months preparing their networks and educating consumers. Consumer education plans will be reviewed by the Public Service Commission.

Q: When will 10-digit dialing begin?

A: 10-digit dialing will begin in mid-2014, after the six-month consumer education period, but it won’t be mandatory until roughly the end of the year. The phase-in period is to get people used to the idea of dialing an area code to make local calls within the 843 area. During the second half of 2014, calls within the 843 area code may be dialed with either 10 digits or seven.

Q: Will this change the cost of local calls?

A: No.

Q: Will people with 843 numbers have to do anything differently, other than dialing more digits?

A: Many people and businesses will need to reprogram equipment that uses phone numbers, such as alarm systems and fax machines, to include an area code. Some businesses may need to upgrade or modify existing systems.

Q: When South Carolina previously outgrew area codes, the state was divided up and different areas got different area codes. Why is it different this time?

A: Splitting the 843 area code and creating an east-west boundary somewhere between Georgetown and McClellanville was considered, but the telephone industry preferred an overlay, and the commission approved that request unanimously.

Through 1995 South Carolina had just one area code, 803. Growth of the population and of electronic devices increased demand for phone numbers, and by 1998 the state had been divided into three regions, each with its own area code. These days, overlay area codes are preferred; splitting an area would require roughly half the people to change their phone numbers.

Q: When will phone numbers with the new area code be available?

A: Starting one month after mandatory 10-digit dialing begins, so roughly around the end of January 2015.

Q: How long until the 843 area needs a third area code?

A: The second area code is expected to satisfy the region’s demand for phone numbers for 28 years.

Q: How many telephone numbers does one area code account for?

A: Some combinations aren’t used, such as prefixes that begin with zero, or reserved prefixes such as 911. After those are subtracted, each area code is good for 7.92 million numbers, according to the North American Numbering Plan administrator, Neustar.

Q: Why don’t we know what the new area code number will be?

A: It hasn’t been made public by Neustar. The number will be established at least 90 days before the “permissive dialing” phase-in period begins in mid-2014.

Reach David Slade at 937-5552