| Term | Definition / Meaning / Stand for |
| TTB |
Alcohol and Tobacco Tax and Trade Bureau |
| TCA |
Tax Court Assistance |
| TCA |
Tax Court of Appeals |
| TIA |
Tax Increment Area |
| TAR |
Technology Assisted Review (in legal document review) |
| TBR |
Temporary Bankruptcy Relief |
| TBI |
Temporary Bypass Interference |
| TDP |
Temporary Disability Payments |
| TST |
Testimony (in court trials) |
| TPI |
Third-Party Insurance |
| TOL |
Time of Limitation (time limitation in legal claims) |
| TPI |
Tortious Interference (legal term) |
| TLP |
Transactional Law Practice |
| TFA |
Transfer of Assets (used in estate planning) |
| TAC |
Trial Advocacy Course |
| TLR |
Trial Litigation Reporting |
| TRC |
Trial Review Committee |
| TNVAT |
Tamil Nadu Value Added Tax |
| TAN |
Tax Account Number |
| TIN |
Tax Information Network |
| TIN |
Taxpayer Identification Number |
| TCPA |
Telephone Consumer Protection Act |
| TRO |
Temporary Restraining Order |
| TLC |
Tender Loving Care (in family law, often regarding child custody) |
| TPA |
Third-Party Administrator |
| TBD |
To Be Determined (used in scheduling hearings) |
| TASEP |
Totally Asymmetric Simple Exclusion Process |
| TNN |
Totally No Noise |
| TAA |
Trade Adjustment Assistance |
| TPA |
Trade Promotion Authority |
| TM |
TradeMark |
| TPP |
Trans-Pacific Partnership (trade law) |
| TBI |
Traumatic Brain Injury (personal injury law) |