Significant events for area code 210
| Date |
Details |
| November 1, 1992 | Area code 512 was split with 210 covering the western area |
| July 7, 1997 | Three-way split of area code 210. The area surrounding San Antonio and extemding west to the Gulf moving to 830 and the southern area moving to 956 |
| October, 2017 | Area code 726 is planned to be overlaid on 210 in October |