| Acronym | Definition |
|---|
| TAN | Tangent |
| TAN | Total Acid Number |
| TAN | Tough as Nails |
| TAN | Transaktionsnummer (German: Transaction Number) |
| TAN | Tooth and Nail (record company) |
| TAN | Thunderbirds Are Now (band) |
| TAN | Transaction Number |
| TAN | Total Area Network |
| TAN | Test Area North |
| TAN | The Assimilated Negro (blog) |
| TAN | Terrain Aided Navigation |
| TAN | Tax Anticipation Note(s) |
| TAN | Total Ammonia Nitrogen |
| TAN | Total Access Networks, Inc. |
| TAN | The Anime Network |
| TAN | The American Nurse |
| TAN | Tasso Annuale (Italian) |
| TAN | Tax Account Number |
| TAN | Translocation-Associated Notch |
| TAN | Tiny Area Network |
| TAN | Transaction Authorization Number (banking) |
| TAN | Traction Avant Nederland (Dutch automobile club) |
| TAN | Texas Association of Nurserymen |
| TAN | Tape Area Network |
| TAN | Tremor Action Network (Pleasanton, CA) |
| TAN | Treatment Authorization Number (healthcare billing) |
| TAN | Technical Application Note |
| TAN | Table Area Network |
| TAN | Temporary Authorization Number (password with expiration date) |
| TAN | Tactical Area Network |
| TAN | Trunk Appearance Number |
| TAN | Transportation Advisory Notice |
| TAN | Teletype Alert Network |
| TAN | Test Advisory Notice |