CompDefendCheck My Business Tax Defensibility

Business tax library

Understand the IRS issues behind your score.

Every area the CompDefend assessment grades has a body of federal rules behind it. These pages explain those rules in plain language — what the IRS actually requires, what a given notice means, and what the deadline is — so the score has something underneath it you can check for yourself.

Start here

What "defensible" means for a business tax position, what the IRS can see about your account, and what you would be authorizing if you let someone watch it.

  • Business tax defensibility: what it is, and how to measure yours

    Defensibility is how well your business could support its federal tax positions if the IRS asks. What it covers, why it differs from an audit-risk guess, and how to measure yours free.

    GuideLast reviewed

  • What is the Federal Tax Defensibility Index?

    The Federal Tax Defensibility Index (FTDI) is a 0–100 measure of how well your business’s federal tax posture appears supported. What the score means, what confidence means, what missing information does, and what the index does not tell you.

    GuideLast reviewed

  • IRS business account monitoring: what it is and how it works

    Your federal business tax account changes between filings — balances, penalties, exam and collection activity. How monitoring under Form 8821 works, what it can and cannot see, and when it helps.

    GuideLast reviewed

  • Business tax transcripts: what they are and how to read them

    The IRS keeps a transcript of every business tax account. The transcript types, how to request them, what transaction codes mean, and how owners use them to see what the IRS sees.

    GuideLast reviewed

  • Form 8821: what a tax information authorization actually permits

    Form 8821 lets a person or company see your tax information — nothing more. How it differs from Form 2848 power of attorney, what the CAF number is, and how to complete or revoke one.

    GuideLast reviewed

Payroll and the people you pay

Two of the areas where small businesses most often build up quiet exposure: who counts as an employee, and getting deposits in on time.

Running an S corporation

The federal records behind a working owner’s pay: when payroll is required, how W-2, Form 941, Form 940, and Form 1120-S should agree, and what to check when one of them is missing.

When a notice arrives

The IRS says something is owed, missing or wrong. Each page explains what the notice actually means, the deadline printed on it, and what happens if it goes unanswered.

  • How to read an IRS notice

    Read an IRS notice in four passes: notice or letter number, tax form and period, amount or requested action, and the printed deadline. Plus penalty and interest, contact, appeal rights, enclosures, verification, and what to keep.

    GuideLast reviewed

  • Your business received an IRS notice — what to do right now

    A worried business owner has a notice in hand. What to do right now: identify the notice, verify it, find the printed deadline, decide agree-disagree-cannot-pay, and know when to involve a tax professional.

    GuideLast reviewed

  • IRS CP161: your business balance-due notice, explained

    CP161 says your business owes tax, penalties, or interest the IRS believes is unpaid. Why the numbers may differ from your return, payment and dispute options, and what happens next.

    NoticeLast reviewed

  • IRS CP504B: what this intent-to-levy notice really means

    CP504B is a final balance-due warning before the IRS can levy certain business property. What it can and cannot seize at this stage, your payment options, and what comes next.

    NoticeLast reviewed

  • IRS CP259: the IRS thinks a business return is missing

    CP259 means the IRS expected a business return it never received. Why filing requirements linger after closures and S elections, and how to respond before penalties compound.

    NoticeLast reviewed

  • IRS CP162: late, incomplete, and required e-filing penalties

    CP162 assesses penalties for late, incomplete, or improperly paper-filed 1120-S and 1065 returns. How the amount is computed, current administrative relief, and how to respond.

    NoticeLast reviewed

  • IRS CP2100 and the B notice: what your business must do

    A CP2100 or CP2100A means payee names and TINs on your 1099s did not match IRS records. The 15-business-day B notice step, backup withholding, and how to fix it — explained.

    NoticeLast reviewed

  • Notice 972CG: the proposed information-return penalty, explained

    Notice 972CG proposes a penalty for late, incorrect, or missing 1099s and other information returns. The 45-day response window, reasonable-cause relief, and how to respond.

    NoticeLast reviewed

When an examination starts

A letter proposing an audit, or an examiner asking for records. What stage each one represents, and what is being asked for.

Not sure which of these applies to you?

The free assessment adapts to your business and grades only the areas you actually owe. It names the weak ones, and points at the page that explains each.

Check My Business Tax Defensibility