This table shows local area codes and prefixes. The area code makes up the first 3 digits of a 10 digit number, and the prefix makes up the next 3 digits. The Local Calling Area is subject to change without notice. Check this site at any time for the most up-to date listings.
| Exchange | In Area Code | Prefixes |
| Chatham | 973 | 309 457 507 635 665 701 738 |
| Livingston | 862 | 223 485 |
| 973 | 251 322 369 422 436 486 488 533 535 548 577 597 629 712 716 740 758 863 885 974 992 994 | |
| Madison | 862 | 204 |
| 973 | 210 236 245 261 264 295 301 307 360 377 408 410 437 443 514 520 549 593 660 765 805 822 845 937 966 | |
| Millburn | 862 | 206 |
| 973 | 218 232 258 314 315 346 376 379 467 544 564 671 788 912 921 924 | |
| Morristown | 201 | 213 274 323 400 404 412 415 454 486 506 513 572 602 650 715 738 771 787 826 859 910 919 924 |
| 862 | 222 242 579 812 | |
| 973 | 203 206 207 214 216 223 224 254 267 269 270 285 290 292 294 326 349 355 359 385 387 397 401 407 441 449 451 452 455 462 476 490 496 499 525 532 536 538 539 540 590 605 606 610 615 630 631 644 647 656 682 683 695 698 714 722 723 727 734 753 760 769 775 796 801 819 828 829 867 871 879 886 889 892 898 906 944 946 960 964 967 971 975 978 984 993 998 | |
| South Orange | 862 | 205 |
| 973 | 275 313 327 378 382 761 762 763 821 833 843 913 996 | |
| Whippany | 862 | 701 778 |
| 973 | 201 215 240 319 386 428 434 463 503 515 526 560 561 576 581 585 599 602 637 739 781 793 795 884 887 888 929 947 952 |