| 1 | BLA | All Charter Limited | Callsign: All Charter, Ceased operations. | GB | AVCODES |
| 2 | BLA | Blue Air Aviation S.A. | IATA: 0B, Callsign: Blue Air, IATA Prefix: 475, Suspended operations on 06 September 2022. ICAO code changed from BMS and ICAO callsign changed to Blue Messanger w.e.f. 18 February 2020. Name changed from Blue Air - Airline Management Solution S.R.L. w.e.f. 03 August 2018. | RO | AVCODES |
| 3 | BLA | All Charter Limited | | | ICAO1 |
| 4 | BLA | The Baltimore and Annapolis R.R. Co. | 1/1975-1/1980; eliminated 10/1991 | | NAKINA |
| 5 | BLA | The Baltimore and Annapolis R.R. Co. | 1/75-1/80; eliminated 10/91 | | NRHS |
| 6 | BLA | RETIRED 04-15-93 ATP (0053) [BALTIMORE & ANNAPOLIS RR.] | | | PWRC |
| 7 | BLA | Baltimore and Annapolis Railroad | | | RSRV |
| 8 | BLA | BELLAIR CHARTERS | | | SCAC4 |
| 9 | BLA | The Baltimore and Annapolis R.R. Co. | | USA | TRAFFIC |
| 10 | BLAB | BLAND TAXI COMPANY | | | SCAC3 |
| 11 | BLAC | B-LAK LOGISTIC SERVICES INC | | | SCAC4 |
| 12 | BLAE | BLAIR, EDDIE R | | | SCAC3 |
| 13 | BLAF | BLASER FARMS | | | SCAC3 |
| 14 | BLAG | BAL TRANSPORT INC | | | SCAC4 |
| 15 | BLAG | Blaguss Reisen GmbH | | A | TRAFFIC |
| 16 | BLAGSK | Blaguss Slovakia | | SK | TRAFFIC |
| 17 | BLAH | BLACKMON TRUCKING INC | | | SCAC3 |
| 18 | BLAI | BLAIR, E M | | | SCAC3 |
| 19 | BLAJ | BARRIER, L A & SON INC | | | SCAC4 |
| 20 | BLAL | BLALOCK EQUIPMENT CORPORATION | | | SCAC4 |
| 21 | BLAM | BAKERSFIELD-L A MOTOR EXPRESS | | | SCAC3 |
| 22 | BLAN | BLACKWELL OIL COMPANY INC | | | SCAC4 |
| 23 | BLAND | Bernhard Landers GmbH | | DE | VKM |
| 24 | BLAO | BLANCK & SONS DELIVERY SERVICE | | | SCAC3 |
| 25 | BLAP | BLAKLEY TRANSPORTATION INC | | | SCAC3 |
| 26 | BLAQ | BLACK TRANSFER & STORAGE CO INC | | | SCAC3 |
| 27 | BLAS | BLASCHKE TRUCKING COMPANY | | | SCAC3 |
| 28 | BLAS | BLASCHKE TRUCKING COMPANY | | | SCAC4 |
| 29 | BLAU | AGENCIA CASAS | | | SCAC3 |
| 30 | BLAUS | Busunternehmen Bendorfer- Lausjung GmbH & Co | | D | TRAFFIC |
| 31 | BLAV | BLAIRSVILLE TRANSPORT INC | | | SCAC3 |
| 32 | BLAV | BLACKHAWK TRANSPORT LLC | | | SCAC4 |
| 33 | BLAW | BARO, LAWRENCE D | | | SCAC3 |
| 34 | BLAX | RAILCAR INNOVATIONS LLC | | | SCAC4 |
| 35 | BLAY | BLANEY FARMS INC | | | SCAC3 |
