Worth watching
Transcript Code 300: Additional Tax/Assessment by Examination
Additional assessment from an audit or CP2000.
How to read your transcript: pull your Account Transcript free at irs.gov → "Get Transcript." Each line is a transaction code with a date. Codes post in order — a 570 (freeze) followed by a 571 (resolved) followed by an 846 (refund issued) is the classic sequence.
All transaction codes
150 Return Filed & Assessment151 Taxpayer Data Deleted290 Additional Tax Assessed291 Tax Abated420 Examination Indicator421 Examination Closed424 Examination Request425 Examination Indicator Transferred560 Return Freeze/Status Change570 Additional Account Action Pending / Freeze571 Freeze Resolved610 Payment with Return611 Payment Dishonored670 Payment Posted766 Credit to Your Account768 Earned Income Credit806 W-2/1099 Withholding810 Refund Freeze811 Refund Freeze Released820 Refund Canceled826 Credit Transferred Out836 Refund Deposited to Debt846 Refund Issued898 Refund Offset (BFS/TFMS)899 Offset Refund Transfer960 Appointed Representative (2848)961 Revoked POA971 Notice Issued976 Duplicate Return Filed977 Amended/Duplicate Return Posted