Editing Seven-digit dialing (section)

===1981 to 1994===
New area code assignments were increasing in the 1980s. From 1990 to 1994, all remaining assignable codes entered service. The exhaustion of NXX codes necessitated interchangeable codes in several more area codes. Ten-digit dialing, or 1+10D, was implemented in area codes with interchangeable NXX codes. Protected dialing plans as in national capital areas were discontinued to help meet demand without area code relief. As 1994 neared its end, ten-digit dialing became required throughout the numbering plan in preparation for interchangeable NPA codes.

All local numbers now had seven-digit, as the last technological hold-outs had given way to modern switching technology. The concept of a ten-digit local number was conceived, as New York had an overlay code (917, implemented in 1992), but seven-digit dialing was still the norm.