Links to: AB-AG AG-AL, AL-AN, AP-AS, AS-AX
| 505117 | ALLOYS (WHOLESALE) | 259 | 311 | |
| B | ALLSTATE | 5 | 6 | |
| B | ALLSTATE | 1 | 1 | |
| B | ALLSTATE | 8 | 10 | |
| B | ALLSTATE | 24 | 29 | |
| B | ALLSTATE | 27 | 32 | |
| B | ALLSTATE | 11819 | 14183 | |
| E | ALPHA BETA | 2 | 2 | |
| 2 | ALPHA GRAPHICS | 229 | 275 | |
| 569932 | ALTERATIONS-CLOTHING | 10321 | 12385 | |
| G | ALTERNATIVE | 2203 | 2644 | |
| 804946 | ALTERNATIVE HEALING SERVICES | 3 | 4 | |
| 369404 | ALTERNATORS & GENERATORS AUTOMOTIVE-MFRS | 56 | 67 | |
| 753908 | ALTERNATORS & GENERATORS AUTOMOTIVE-RPR | 1131 | 1357 | |
| 501340 | ALTERNATORS & GENERATORS AUTOMOTIVE-WHOL | 60 | 72 | |
| 553105 | ALTERNATORS & GENERATORS-AUTOMOTIVE | 2813 | 3376 | |
| 369405 | ALTERNATORS & STARTERS-MARINE (MFRS) | 356 | 427 | |
| G | ALTOS | 17 | 20 | |
| 505128 | ALUMINUM (WHOLESALE) | 2898 | 3478 | |
| 3363 | ALUMINUM DIE CASTINGS | 459 | 551 | |
| 336398 | ALUMINUM DIE CASTINGS (MANUFACTURERS) | 459 | 551 | |
| 3354 | ALUMINUM EXTRUDED PRODUCTS | 461 | 553 | |
| 335498 | ALUMINUM EXTRUDED PRODUCTS (MFRS) | 461 | 553 | |
| 335501 | ALUMINUM FABRICATORS | 1105 | 1326 | |
| 3365 | ALUMINUM FOUNDRIES | 1342 | 1610 | |
| 344613 | ALUMINUM ORNAMENTAL WORK (MFRS) | 9 | 11 | |
| 571982 | ALUMINUM PRODUCTS-RETAIL | 62 | 74 | |
| 3355 | ALUMINUM ROLLING & DRAWING NEC | 1221 | 1465 | |
| 335598 | ALUMINUM ROLLING & DRAWING NEC (MFRS) | 117 | 140 | |
| 3353 | ALUMINUM SHEET PLATE & FOIL | 160 | 192 | |
| 335301 | ALUMINUM SHEET ROD & ETC (MFRS) | 160 | 192 | |
| 329103 | ALUMINUM WOOL-MANUFACTURERS | 1 | 1 | |
| 281902 | ALUM-MANUFACTURERS | 8 | 10 | |
| 832258 | ALZHEIMERS EDUCATION/REFERRAL/SUPPORT | 130 | 156 | |
| 1 | AM STATIONS | 2181 | 2617 | |
| B | AMANA | 617 | 740 | |
| B | AMANA | 136 | 163 | |
| B | AMANA | 1094 | 1313 | |
| B | AMANA | 253 | 304 | |
| B | AMANA | 56 | 67 | |
| 506526 | AMATEUR RADIO EQUIPMENT (WHOLESALE) | 2 | 2 | |
| 411902 | AMBULANCE SERVICE | 5774 | 6929 | |
| 501202 | AMBULANCES & HEARSES (WHOLESALE) | 184 | 221 | |
| 501366 | AMBULANCES & HEARSES EQUIP/SUPLS (WHOL) | 3 | 4 | |
| 371105 | AMBULANCES & HEARSES-MANUFACTURERS | 42 | 50 | |
| 411905 | AMBULETTE SERVICE | 252 | 302 | |
| A | AMERICAN BUILDINGS | 339 | 407 | |
| 8 | AMERICAN FAMILY | 6 | 7 | |
| 8 | AMERICAN FAMILY | 6 | 7 | |
| 8 | AMERICAN FAMILY | 13 | 16 | |
| 8 | AMERICAN FAMILY | 13 | 16 | |
| 8 | AMERICAN FAMILY | 2953 | 3544 | |
| A | AMERICAN LEGION | 424 | 509 | |
| A | AMERICAN LEGION | 1523 | 1828 | |
| C | AMERICAN SPEEDY PRINTING | 338 | 406 | |
| A | AMES | 253 | 304 | |
| 516914 | AMMONIA (WHOLESALE) | 87 | 104 | |
| 287302 | AMMONIA-MANUFACTURERS | 7 | 8 | |
| 594145 | AMMUNITION | 693 | 832 | |
| 509338 | AMMUNITION DISASSEMBLY WST/RECYCLE (WHL) | 2 | 2 | |
| G | AMMUNITION RELOADING | 28 | 34 | |
| 348404 | AMMUNITION RELOADING EQUIP & SUPLS-MFRS | 6 | 7 | |
| 594144 | AMMUNITION RELOADING EQUIPMENT & SUPLS | 383 | 460 | |
| 3483 | AMMUNITION-EXCEPT FOR SMALL ARMS | 96 | 115 | |
| 348398 | AMMUNITION-EXCEPT FOR SMALL ARMS (MFRS) | 92 | 110 | |
| 348201 | AMMUNITION-MANUFACTURERS | 141 | 169 | |
| 509122 | AMMUNITION-WHOLESALE | 15 | 18 | |
| B | AMOCO | 4911 | 5893 | |
| 501203 | AMPHIBIOUS VEHICLES (WHOLESALE) | 3 | 4 | |
| 573605 | AMPLIFIERS | 79 | 95 | |
| 365115 | AMPLIFIERS-MANUFACTURERS | 6 | 7 | |
| 799999 | AMUSEMENT & RECREATION NEC | 1452 | 1742 | |
| 79 | AMUSEMENT & RECREATION SERVICES | 196166 | 235399 | |
| 7999 | AMUSEMENT & RECREATION SERVICES NEC | 99352 | 119222 | |
| 0 | AMUSEMENT AND RECREATION NEC | 1145 | 1374 | |
| 799301 | AMUSEMENT DEVICES | 3075 | 3690 | |
| 399907 | AMUSEMENT DEVICES-MANUFACTURERS | 15 | 18 | |
| 799307 | AMUSEMENT DEVICES-RENTING | 11 | 13 | |
| 509920 | AMUSEMENT DEVICES-WHOLESALE | 28 | 34 | |
| 508747 | AMUSEMENT PARK RIDES EQUIPMENT (WHOL) | 325 | 390 | |
| 7996 | AMUSEMENT PARKS | 7338 | 8806 | |
| 799601 | AMUSEMENT PLACES | 7322 | 8786 | |
| 382305 | ANALYZERS-INDUSTRIAL CONTROL-MFRS | 14 | 17 | |
| 555117 | ANCHORS | 4 | 5 | |
| 344101 | ANCHORS-EXPANSION (MANUFACTURERS) | 159 | 191 | |
| 555114 | ANCHORS-MARINE | 24 | 29 | |
| 861105 | ANCSA NATIVE CORPORATIONS | 126 | 151 | |
| 382919 | ANEMOMETERS (MANUFACTURERS) | 2 | 2 | |
| 8 | ANESTHESIOLOGY | 4055 | 4866 | |
| 801108 | ANESTHETISTS | 114 | 137 | |
| 342913 | ANGLE IRONS (MANUFACTURERS) | 4 | 5 | |
| 2077 | ANIMAL & MARINE FATS & OILS | 625 | 750 | |
| 207798 | ANIMAL & MARINE FATS & OILS (MFRS) | 76 | 91 | |
| 0273 | ANIMAL AQUACULTURE | 91 | 109 | |
| 027905 | ANIMAL BREEDING-SMALL | 176 | 211 | |
| 029102 | ANIMAL BROKERS & DEALERS-ZOO CIRCUS ETC | 52 | 62 | |
| 519960 | ANIMAL CAGES & RACKS-WHOLESALE | 4 | 5 | |
| 207701 | ANIMAL CARCASS REMOVAL | 141 | 169 | |
| 519126 | ANIMAL FOODS-ZOO & CIRCUS & ETC (WHOL) | 24 | 29 | |
| 519108 | ANIMAL HEALTH PRODUCTS (WHOLESALE) | 866 | 1039 | |
| 204801 | ANIMAL HEALTH PRODUCTS-MANUFACTURERS | 75 | 90 | |
| 074203 | ANIMAL HOSPITALS | 14119 | 16943 | |
| 075216 | ANIMAL NUTRITIONIST CONSULTANTS | 19 | 23 | |
| 869909 | ANIMAL PROTECTION ORGANIZATIONS | 71 | 85 | |
| 075213 | ANIMAL REGISTRATION & IDENTIFICATION SVC | 38 | 46 | |
| 097103 | ANIMAL RESCUE RELOCATION & TRANSPORTING | 57 | 68 | |
| 075203 | ANIMAL SHELTERS | 1292 | 1550 | |
| 0279 | ANIMAL SPECIALTIES NEC | 1180 | 1416 | |
| 027999 | ANIMAL SPECIALTIES NEC | 116 | 139 | |
| 0752 | ANIMAL SPECIALTY SVCS-EXCEPT VETERINARY | 37469 | 44963 | |
| 519127 | ANIMAL SUPPLIES-ZOO CIRCUS ETC (WHOL) | 7 | 8 | |
| 421224 | ANIMAL TRANSPORTING-ZOO CIRCUS ETC | 11 | 13 | |
| 027903 | ANIMALS-LABORATORY USE | 17 | 20 | |
| 734212 | ANIMALS-PEST TRAPPERS | 285 | 342 | |
| 781212 | ANIMATED FILM SERVICES | 150 | 180 | |
| 399306 | ANIMATION MECHANISMS-DISPLAY SIGN (MFRS) | 34 | 41 | |
| 275216 | ANNOUNCEMENTS (MANUFACTURERS) | 20 | 24 | |
| 382301 | ANNUNCIATORS-MANUFACTURERS | 7 | 8 | |
| 506535 | ANNUNCIATORS-WHOLESALE | 8 | 10 | |
| 505118 | ANODES (WHOLESALE) | 27 | 32 | |
| 364306 | ANODES-MANUFACTURERS | 4 | 5 | |
| 347101 | ANODIZING (MANUFACTURERS) | 415 | 498 | |
| 599901 | ANSWERING MACHINES-AUTOMATIC | 195 | 234 | |
| 573101 | ANTENNAS | 3252 | 3902 | |
| 367904 | ANTENNAS-MANUFACTURERS | 43 | 52 | |
| 484102 | ANTENNAS-TELEVISION COMMUNITY SYSTEMS | 46 | 55 | |
| 506536 | ANTENNAS-WHOLESALE | 7 | 8 | |
| 1231 | ANTHRACITE MINING | 66 | 79 | |
| 123198 | ANTHRACITE MINING | 66 | 79 | |
| 289923 | ANTI-FOGGING COMPOUNDS-MANUFACTURERS | 1 | 1 | |
| 289902 | ANTI-FREEZE COMPOUNDS-MANUFACTURERS | 49 | 59 | |
| 516955 | ANTI-FREEZE COMPOUNDS-WHOLESALE | 5 | 6 | |
| 593202 | ANTIQUES-DEALERS | 39178 | 47014 | |
| 764112 | ANTIQUES-REPAIRING & RESTORING | 5835 | 7002 | |
| 593209 | ANTIQUES-REPRODUCTIONS | 792 | 950 | |
| 525116 | ANTIQUES-RESTORATION SUPPLIES & HARDWARE | 7 | 8 | |
| 593210 | ANTIQUES-WHOLESALE | 301 | 361 | |
| C | ANTI-TRUST LICENSING | 581 | 697 | |
| 346204 | ANVILS (MANUFACTURERS) | 1 | 1 |