| Abbreviation | Definition |
|---|---|
| 1065 | Form 1065 - U.S. Federal Tax Return of Partnership Income - The federal Income Tax form Partnerships |
| 1120 | Form 1120 - The US Federal Business Income Tax form for Corporations to file annually with the IRS w |
| 1120S | Form 1120-S, U.S.Federal Income Tax Return for an S-Corporation - The US Federal Business Income Tax |
| AATP | American Academy Of Tax Practice |
| ABOC | Automobile Benefits Online Calculator |
| ABST | Antigua and Barbuda Sales Tax |
| ABST | Antigua Barbuda Sales Tax |
| ACAUT | Action Committee Against Unabated Taxation |
| ACAUT | Against Corruption And Unabated Taxation |
| ACIT | Additional Commissioner of Income Tax |
| ACIT | Assistant Commissioner of Income Tax |
| ACTC | American College of Tax Counsel |
| ACTF | American - China Trade Friction |
| ACTL | Amsterdam Centre for Tax Law |
| AFFT | Americans For Fair Taxation |
| AFTC | Alternative Fuel Tax Credit |
| AHTC | Affordable Housing Tax Credits |
| AIT | All Included Taxes |
| AIT | Application of Internal Taxes |
| AITD | Angel Investors Tax Deduction |