Prefix Telephone Company 200 Teledial America 201 800 Database 202 Radio Common Carrier 203 Sonic Communications 204 205 206 207 208 209 210 211 212 Radio Common Carrier 213 Cincinnati Bell Telephone 214 215 216 217 Phoenix Communications 218 219 220 ATX Telecommunications Services 221 AT&T 222 AT&T 223 AT&T 224 LDDS Communications 225 AT&T 226 Advanced Telecommunications 227 AT&T 228 AT&T 229 Cable & Wireless Communications 230 One 2 One Communications 231 AT&T 232 AT&T 233 AT&T 234 MCI 235 AT&T 236 Schneider Communications 237 AT&T 238 AT&T 239 Delta Communications 240 Southern Interexchange Service 241 AT&T 242 AT&T 243 AT&T 244 800 Database 245 AT&T 246 800 Database 247 AT&T 248 AT&T 249 Telecom West 250 800 Database 251 AT&T 252 AT&T 253 AT&T 254 Total Telephone United States Of America 255 AT&T 256 Long Distance Savers 257 AT&T 258 AT&T 259 Long Distance Savers 260 LDDS Communications 261 Schneider Communications 262 AT&T 263 Telecom Canada 264 LDDS Communications 265 Telecom Canada 266 Com Systems 267 Telecom Canada 268 Telecom Canada 269 ABCO Communications 270 Cleartel Communications 271 Telecom Servies Of Trinidad & Tobago 272 AT&T 273 800 Database 274 MCI 275 Metromedia Communications 276 One Call Communications/Tri Tell 277 Telecom United States Of America 278 Call United States Of America 279 LDDS Communications 280 LDDS Communications 281 800 Database 282 AT&T 283 MCI 284 MCI 285 MCI 286 800 Database 287 800 Database 288 MCI 289 MCI 290 291 292 AT&T 293 One 2 One Communications 294 LCI International/Litel 295 ACC Long Distance 296 Long Distance Services 297 American Express Transmission 298 LDDS Communications 299 Advanced Telecommunications 300 800 Database 301 302 Radio Common Carrier 303 800 Database 304 305 306 307 308 Custom Telecommunications Network 309 310 800 Database 311 312 Radio Common Carrier 313 314 315 316 317 318 319 320 Conquest Long Distance 321 AT&T 322 AT&T 323 AT&T 324 Wiltel Long Distance 325 AT&T 326 United States Sprint 327 AT&T 328 AT&T 329 Advanced Telecommunications 330 Advanced Telecommunications 331 AT&T 332 AT&T 333 MCI 334 AT&T 335 Schneider Communications 336 AT&T 337 First Data Resources 338 AT&T 339 800 Database 340 United States Sprint 341 AT&T 342 AT&T 343 AT&T 344 AT&T 345 AT&T 346 AT&T 347 United States Sprint 348 AT&T 349 Network Long Distance 350 Com Systems 351 AT&T 352 AT&T 353 Schneider Communications 354 AT&T 355 ATX Telecommunications Services 356 AT&T 357 Can Net Systems 358 AT&T 359 US Sprint 360 Chadwick Long Distance 361 Telecom Canada 362 AT&T 363 Telecom Canada 364 Wiltel Long Distance 365 MCI 366 United States Sprint 367 AT&T 368 AT&T 369 Teleconnect 370 Advanced Telecommunications 371 800 Database 372 AT&T 373 Teleconnect 374 MCI 375 Advanced Telecommunications 376 Econo Call Long Distance Services 377 United States Sprint 378 800 Database 379 Eastern Microwave 380 381 Long Distance Of Michigan 382 AT&T 383 Teleconnect 384 Voicecomm Systems 385 386 Telecable 387 Telecom Canada 388 MCI 389 Bahamas Telecommunications 390 Econo Call Long Distance Services 391 392 AT&T 393 Phone One 394 Cable & Wireless Communciations 395 MCI 396 United States Telecom 397 Teleconnect 398 United States Sprint 399 Americall 400 800 Database 401 402 Radio Common Carrier 403 404 800 Database 405 Acacia Telephone & Communications 406 407 408 409 410 411 412 Radio Common Carrier 413 414 415 416 417 418 419 420 Advanced Telecommunications 421 AT&T 422 AT&T 423 AT&T 424 AT&T 425 Telephone Tech 426 AT&T 427 800 Database 428 AT&T 429 T Tel 430 431 AT&T 432 AT&T 433 AT&T 434 Amerigon 435 AT&T 436 MCI 437 AT&T 438 AT&T 439 800 Database 440 Tex Net 441 AT&T 442 AT&T 443 AT&T 444 MCI 445 AT&T 446 AT&T 447 AT&T 448 AT&T 449 United Telecommunications 450 United States Link Long Distance 451 AT&T 452 AT&T 453 AT&T 454 Allnet Communications 455 LDD 456 MCI 457 AT&T 458 AT&T 459 United States West 460 United States Long Distance 461 Telecom Canada 462 AT&T 463 Telecom Canada 464 800 Database 465 Telecom Canada 466 Allnet Communications 467 LDDS Communications 468 AT&T 469 Iowa Network Services 470 471 Allnet Communications 472 AT&T 473 United States Sprint 474 Virgin Islands Telephone 475 Teleconnect 476 Teleconnect 477 MCI 478 Alascom 479 800 Database 480 Cable & Wireless Communications 481 800 Database 482 AT&T 483 800 Database 484 Teleconnect 485 Teleconnect 486 Cable & Wireless Communications 487 United States Sprint 488 United States Sprint 489 LDDS Communications 490 491 800 Database 492 AT&T 493 International Pacific 494 Network Telephone Services 495 Southwest Long Distance Network 496 Telefonica Long Distance 497 United States Sprint 498 800 Database 499 800 Database 500 Consolidated Network 501 502 Radio Common Carrier 503 504 Cooperative Long Distance Services 505 Western Long Distance 506 507 508 509 AT&T 510 511 512 Radio Common Carrier 513 514 515 516 517 518 519 520 Pentagon Computer Data 521 AT&T 522 AT&T 523 AT&T 524 AT&T 525 AT&T 526 AT&T 527 AT&T 528 AT&T 529 Midco Communications 530 Vartec National 531 AT&T 532 AT&T 533 AT&T 534 Barbados External Telecommunications 535 AT&T 536 Allnet Communications 537 AT&T 538 AT&T 539 Advanced Telecommunications 540 800 Database 541 AT&T 542 AT&T 543 AT&T 544 AT&T 545 AT&T 546 United States Sprint 547 AT&T 548 AT&T 549 Call America 550 Call America 551 AT&T 552 AT&T 553 AT&T 554 AT&T 555 AT&T 556 AT&T 557 Allnet Communications 558 AT&T 559 800 Database 560 800 Database 561 Telecom Canada 562 AT&T 563 Telecom Canada 564 800 Database 565 Telecom Canada 566 Allnet Communications 567 Telecom Canada 568 MCI 569 Wiltel Long Distance 570 800 Database 571 572 AT&T 573 800 Database 574 Access Long Distance 575 Unitel Communications 576 West Coast Telecommunications 577 Telenet Communication Corporation 578 United States Sprint 579 Lintel Systems 580 Westel 581 Telco 582 AT&T 583 Vartec 584 Teleconnect 585 800 Database 586 Action Telcom 587 LTS 588 Action Telcom 589 LCI International/Litel 590 591 592 AT&T 593 Teleconnect 594 Teleconnect 595 Puerto Rico Telephone 596 Telecom Options Plus 597 United States Sprint 598 United States Sprint 599 Long Distance Management 600 Call America 601 602 Radio Common Carrier 603 Innovative Telecom 604 605 Express Communications 606 800 Database 607 608 609 610 611 612 Radio Common Carrier 613 614 615 616 617 618 619 620 Arvig Telephone 621 AT&T 622 AT&T 623 Bermuda Telephone 624 AT&T 625 National Data 626 AT&T 627 MCI 628 AT&T 629 Beehive Telephone 630 Rural Cellular/Switch 2000 631 AT&T 632 AT&T 633 AT&T 634 AT&T 635 AT&T 636 Conquest Communications 637 AT&T 638 AT&T 639 Response Telecom 640 800 Database 641 AT&T 642 AT&T 643 AT&T 644 Call America 645 AT&T 646 Union Telephone 647 AT&T 648 AT&T 649 800 Database 650 Bridge Water Telephone 651 652 AT&T 653 United States Sprint 654 AT&T 655 Execuline 656 Amvox/Voice Tel 657 Teleconnect 658 Teleconnect 659 United States Sprint 660 800 Database 661 Telecom Canada 662 AT&T 663 Telecom Canada 664 Fox Communications 665 Telecom Canada 666 MCI 667 Telecom Canada 668 Telecom Canada 669 United States Sprint 670 671 Farmers Telephone Coooperative 672 AT&T 673 Teleconnect 674 Teleconnect 675 800 Database 676 United States Sprint 677 MCI 678 MCI 679 Carrier Services 680 Pacific Telephone 681 682 AT&T 683 Metromedia Communications 684 Northern Telecom 685 MCI 686 LCI International/Litel 687 NTS Communications 688 MCI 689 Northwest Telecommunications 690 800 Database 691 Puerto Rico Telephone 692 AT&T 693 LCI International/Litel 694 Telescan 695 MCI 696 800 Database 697 United States Sprint 698 800 Database 699 Pilgrim Telephone 700 Telecor 701 Polar Communications 702 Radio Common Carrier 703 704 705 706 707 708 United Telesystems 709 710 711 712 Radio Common Carrier 713 714 715 716 717 Colonial Enterprise 718 719 720 Telemanagement Consulanting 721 Flex Communications 722 AT&T 723 MCI 724 RCI 725 Advanced Telecommunications 726 United States Sprint 727 MCI 728 Teleconnect 729 United States Sprint 730 731 732 AT&T 733 United States Sprint 734 800 Database 735 United States Sprint 736 United States Sprint 737 LDDS Communications 738 LDDS Communications 739 Telecom Canada 740 741 Advanced Telecommunications 742 AT&T 743 United States Sprint 744 Cable & Wireless Communications 745 United States Sprint 746 TRT Telecommunications 747 Teleconnect 748 Vartec 749 Advanced Telecommunications 750 800 Database 751 Codetel 752 AT&T 753 MCI 754 Tel Share 755 United States Sprint 756 MCI 757 TMC 758 United States Sprint 759 MCI 760 761 Alternate Communications Technology 762 AT&T 763 Touch & Save 764 Alascom 765 MCI 766 MCI 767 United States Sprint 768 Telecom United States Of America 769 United States Sprint 770 General Communications 771 Advanced Telecommunications 772 AT&T 773 800 Database 774 TTE 775 United States Sprint 776 United States Sprint 777 MCI 778 United States Sprint 779 Teleconnect 780 Advanced Telecommunications 781 TMC Long Distance 782 AT&T 783 Allnet Communications 784 American Long Lines 785 Sunshine Telephone 786 United States Sprint 787 Mid Atlantic Telecom 788 United States Sprint 789 Tel America 790 791 792 AT&T 793 United States Sprint 794 800 Database 795 United States Sprint 796 797 TMC 798 Teleconnect 799 Napa Valley Telecom Services 800 United States Sprint 801 800 Database 802 Radio Common Carrier 803 804 805 806 807 International 800 Telecommunications 808 Ameritech Audiotex Services 809 St Thomas & San Juan Telephone 810 811 812 Radio Common Carrier 813 814 815 816 817 818 Telecommunications International 819 820 821 AT&T 822 AT&T 823 Touch America 824 AT&T 825 MCI 826 AT&T 827 United States Sprint 828 AT&T 829 United States Sprint 830 831 AT&T 832 AT&T 833 AT&T 834 800 Database 835 AT&T 836 RCI Long Distance 837 LCI International/Litel 838 United Inter Mountain Telephone 839 Star Line 840 841 AT&T 842 AT&T 843 AT&T 844 LDDS Communications 845 AT&T 846 MCI 847 AT&T 848 AT&T 849 Business Telecom 850 Digitel 851 AT&T 852 AT&T 853 Universal Communications 854 AT&T 855 AT&T 856 American Telco 857 Teleconnect 858 AT&T 859 United States Sprint 860 LCI International/Litel 861 862 AT&T 863 Allnet Communications 864 Wiltel Long Distance 865 Hawaiian Telephone 866 MCI 867 Vortel 868 Telecom United States Of America 869 United States Sprint 870 800 Database 871 Digital Network 872 AT&T 873 MCI 874 AT&T 875 Allnet Communications 876 MCI 877 United States Sprint 878 Allnet Communications 879 MCI 880 LDDS Communications 881 National Telecommunications 882 AT&T 883 Cable & Wireless Communications 884 Firest Financial Management 885 Televue 886 Allnet Communications 887 Eastern Telephone Systems 888 MCI 889 Pacific Telecom 890 ATX Telecommunications Services 891 Com Systems 892 AT&T 893 894 800 Database 895 896 Tex Net Incorporated 897 Northern Arizona Long Distance 898 Communications Group 899 Cable & Wireless Communications 900 Lufkin Telecommunications 901 902 Radio Common Carrier 903 904 905 906 907 Telepuerto San Isidro 908 Ameritech Audiotex Services 909 Call Savers 910 911 912 Radio Common Carrier 913 914 915 916 917 918 919 Marathon Communications 920 921 922 AT&T 923 Allnet Communications 924 800 Database 925 MCI 926 MCI 927 United States Sprint 928 Advanced Telecommunications 929 Metromedia Communications 930 931 932 AT&T 933 MCI 934 MCI 935 Chernow Communications 936 R Communications Long Distance Telephone 937 MCI 938 Metromedia Communications 939 Telenational Communications 940 Advanced Telecommunications 941 Westinghouse Communications 942 AT&T 943 AUS Incorporated 944 MCI 945 MCI 946 LDDS Communications 947 MCI 948 LCI International/Litel 949 United States Sprint 950 MCI 951 LDDS Communications 952 AT&T 953 800 Database 954 800 Database 955 MCI 956 800 Database 957 958 959 United States Sprint 960 LDDS Communications 961 962 AT&T 963 State Of California 964 MCI 965 TMC Long Distance 966 Cable & Wireless Communications 967 MCI 968 Teledial America 969 Cable & Wireless Communications 970 971 Telnex 972 AT&T 973 974 800 Database 975 Long Distance Communications 976 977 Call Home America 978 979 Informatics 980 Valu Line 981 Puerto Rico Telephone 982 AT&T 983 AT&T Easylink 984 985 Capital Network System 986 AT&T Easylink 987 Bittle Telecommunications 988 Teleconnect 989 Cable & Wireless Communications 990 Feb Corporation 991 992 AT&T 993 Lake States Communications 994 800 Database 995 United States Sprint 996 Valu Line 997 Deluxe Data Systems 998 United States Sprint 999 MCI