Quick Reference & Core Rules

Welcome to the Quick Reference section. Keep this page open during training or while navigating taxpayer accounts.

🧠 The Golden Rule of Account Research

DO NOT ASSUME FROM A SINGLE CODE

Don't look at a Transaction Code and immediately jump to conclusions!

Always evaluate the full context: TC + Date + Amount + MFT + Tax Period + Surrounding TCs + Freeze/Hold + Action Code

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🔑 Core Statute Dates at a Glance

Code	Full Name	Simple Meaning	Question to Ask	Easy Memory
ASED	Assessment Statute Expiration Date	Deadline for the IRS to assess additional tax	"How long does the IRS have to assess tax?"	A = Assess
CSED	Collection Statute Expiration Date	Deadline to collect an assessed tax liability	"How long does the IRS have to collect?"	C = Collect
RSED	Refund Statute Expiration Date	Deadline for taxpayer to claim a refund/credit	"How long does taxpayer have to claim refund?"	R = Refund
FRZ	Freeze Codes	Restricts normal account/module processing	"What is stopping normal processing?"	FRZ = Stop/Hold

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⚡ High-Frequency "Brain Translations"

TC	Brain Translation	What It Means
150	📝 Original return	Establishes the original tax assessment
290	➕ Additional tax / adjustment	IRS adjusted or assessed additional tax
300	🔎 Exam deficiency	Examination added a tax deficiency
301	➖ Abate exam deficiency	Reverses or lowers exam assessment
570	🛑 Refund/liability hold	Account processing or refund is stopped
571	✅ Release 570 hold	Resolves the 570 freeze
806	💵 Withholding credit	Federal withholding applied to the module
846	💰 Refund issued	Refund check or direct deposit was sent
971	🔖 Action / Reference	Look at the Action Code (AC) to know what happened
976	📄 Duplicate return indicator	Another return posted for the same tax period
977	📄 Amended return indicator	Taxpayer filed Form 1040-X / amended return
520	⚖️ Legal / court condition	Litigation, bankruptcy, or court freeze
521	🔓 Release 520	Releases the legal condition
530	⏸️ Currently Not Collectible	Hardship / collection suspended status
531	🔄 Release 530	Re-opens collection status
560	⏳ Statute-related action	Updates/affects Master File ASED
610	💳 Payment with return	Remittance received with filed return

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👥 Paired Transaction Codes

Always learn these in pairs:

1. Assessment Pair

• TC 300 = Examination deficiency assessed (adds tax)
• TC 301 = Abatement of TC 300 (reduces tax)

2. Refund Hold Pair

• TC 570 = Hold placed on refund/credits
• TC 571 = Release of TC 570 hold

3. Legal / Litigation Pair

• TC 520 = Legal/court condition placed
• TC 521 = Release of TC 520 condition

4. Collection Hardship Pair

• TC 530 = Currently Not Collectible (CNC)
• TC 531 = Reversal/closing of CNC