What is Form ID W-4?
Form ID W-4, the Employee's Withholding Allowance Certificate, is how you tell your employer how much Idaho income tax to withhold. The Idaho State Tax Commission's current file is form EFO00307, revision 04-28-2025: a one-page certificate you give to your employer, with guidance and a worksheet on the back.
Idaho allowances aren't for you or your spouse. Line 1 counts children in your household age 16 or under, plus 2 if you'll file as head of household — or the word Exempt if you had no Idaho tax liability last year and expect none this year. Line 2 is an optional extra amount per paycheck, and the back page has a worksheet for people who are single or married filing separately with more than one job.
FileIt lets you fill out the ID W-4 online in a guided form. It pre-fills your name from the People records in your vault, runs the extra-job worksheet for you and carries the result to line 2, and prints everything into the Tax Commission's own PDF. The finished form is saved in your vault and can be sent for e-signature. FileIt never submits anything to your employer or the Tax Commission.
- Who fills it
- The employee.
- Given to
- Your employer — the form says sign it and give it to your employer.
- When
- When you start a job with Idaho withholding, or when your family, filing status or jobs change.
- Signatures
- The employee signs and dates it under penalties of perjury.
- Edition
- Form ID W-4, EFO00307 04-28-2025.
- Cost
- Free to fill out on any FileIt account.
Who needs to fill out Form ID W-4?
- Employees whose employer withholds Idaho income tax from their wages.
- Parents who want Idaho allowances for children 16 or under, and people filing as head of household.
- Married couples deciding between status B (Married) and C (Married, but withhold at Single rate).
- Single people or married people filing separately who have more than one job at a time.
- Nonresident aliens working in Idaho, who follow the special instructions on the back of the form.
- Anyone who had no Idaho tax liability last year and expects none this year, and wants to claim Exempt.
When to use Form ID W-4
- When you start a new job in Idaho, alongside the federal Form W-4 and Form I-9.
- When you have a child, a child turns 17, or your filing status changes.
- When you start or stop a second job.
- When you qualify, or stop qualifying, for exemption from Idaho withholding.
What you need before you start
- Your Social Security number (the form says it's required), name and mailing address.
- Your expected filing status, to choose box A, B or C.
- The number of children in your household age 16 or under at the end of the year.
- For the extra-job worksheet: how many other jobs you'll have at the same time, your estimated income from them, and the number of pay periods left in the year.
- If you itemize, line 4 of the Itemized Deduction Worksheet for Idaho at tax.idaho.gov/w4.
- If you're a nonresident alien with a tax treaty, federal Form 8233 for the treaty part.
What’s on Form ID W-4
The 2025 edition has 2 pages. FileIt asks for it in 4 parts, and it is signed by Employee:
- Withholding status and allowancesEmployee
- Your name, SSN and addressEmployee
- Line 2 worksheet: more than one jobEmployee
- Sign hereEmployee
How to fill out Form ID W-4, step by step
1 Withholding status A, B or C
A (Single): single with one or more jobs, or filing as head of household. B (Married): married filing jointly with one job and a spouse who doesn't work, or a qualifying surviving spouse with qualifying dependents. C (Married, but withhold at Single rate): married filing jointly where both work (or you have multiple jobs), or married filing separately. A nonresident alien with Idaho taxable income checks A regardless of marital status.
2 Line 1: Allowances or Exempt
Enter the number of children in your household age 16 or under at the end of the year, or 0 if none, and add 2 if you'll file as head of household. Don't claim allowances for yourself or your spouse. You can claim fewer but not more.
If you're married filing jointly, only one of you claims the allowances, on the highest-paying job; the other claims zero. With more than one employer at once, claim zero everywhere except your principal employer. Write Exempt instead only if you had no Idaho income tax liability last year and expect none this year.
3 Line 2: Additional amount
Enter any extra amount to withhold from each paycheck, in whole dollars. If you're single or married filing separately with more than one job at a time, the worksheet on the back works it out: $15,000 for each other job, capped at your income from those jobs, less $3,868 for each allowance from the Itemized Deduction Worksheet, times 5.3%, divided by your remaining pay periods. FileIt does this arithmetic and copies the answer to line 2.
4 Nonresident aliens
If all your income is exempt from withholding, write Exempt on line 1. With Idaho taxable income, check A, enter 0 on line 1, and enter the Pay Period table amount on line 2: $15 weekly, $31 biweekly, $33 semimonthly or $66 monthly (a student or business apprentice from India reports $0).
5 Your details and signature
Enter your Social Security number, name and current mailing address, then sign and date the form. You declare under penalties of perjury that you can claim the allowances on line 1.
Common mistakes to avoid
- Claiming allowances for yourself or your spouse — Idaho allowances are for children 16 or under and head of household status only.
- Both spouses claiming the children's allowances when filing jointly.
- Claiming allowances with a second employer instead of zero.
- Writing Exempt when you had Idaho tax liability last year or expect some this year.
- Entering cents on line 2 — the form asks for whole dollars.
- Leaving out the Social Security number, which the form marks as required.
After you fill it out
Sign and date the certificate and give it to your employer. Keep the worksheet page for your records.
FileIt saves the finished PDF in your vault folder, so you have a record of your status and allowances.
The Tax Commission suggests reviewing your W-4 at least once a year or when your life changes. Its W-4 page links an IRS withholding estimator too.
Fill out Form ID W-4 online with FileIt
- Pick the person. Choose someone from People and FileIt fills in their name, date of birth, address and other details it already knows.
- Answer plain-language questions. One part of the form at a time, with the official help text beside each question — 24 fields in all. Your answers save as you go.
- Check the live preview. Watch your answers land on the real Idaho State Tax Commission form, and let FileIt do any worksheet arithmetic.
- Generate the official PDF. FileIt prints your answers into the agency’s own PDF and files it in that person’s folder in your vault. Sign it, or send it for e-signature.
FileIt fills the form — it never files or submits anything for you. Deliver the finished form to whoever asked for it, the way the form’s instructions say.
Start Form ID W-4 now — it’s freeForm ID W-4: frequently asked questions
What is Form ID W-4?
It is Idaho's Employee's Withholding Allowance Certificate from the Idaho State Tax Commission. It tells your employer how much Idaho income tax to withhold, based on your withholding status, allowances and any additional amount.
How many allowances can I claim on the Idaho W-4?
One for each child in your household age 16 or under at the end of the year, plus 2 if you'll file as head of household. You don't claim allowances for yourself or your spouse, and you can claim fewer but not more.
Should I check B or C on the ID W-4?
B (Married) if you're married filing jointly with one job and your spouse doesn't work, or a qualifying surviving spouse with qualifying dependents. C (Married, but withhold at Single rate) if you both work or you have multiple jobs, or if you're married filing separately.
When can I write Exempt on the Idaho W-4?
When you meet both conditions: you had no Idaho income tax liability last year, and you expect none this year. A nonresident alien whose income is all exempt from withholding also writes Exempt.
Why does the form mention 2025?
The current file from the Idaho State Tax Commission is the 04-28-2025 revision, and its back page refers to 2025. When FileIt checked on 28 September 2026, the Commission had not published a newer revision.
Can I fill out the ID W-4 online?
Yes. FileIt walks you through the form, runs the extra-job worksheet, and prints your answers into the official Idaho PDF. The finished form is saved in your vault and can be sent for e-signature; you give it to your employer yourself.
Official sources
- Blank form (PDF), published by Idaho State Tax Commission: https://tax.idaho.gov/document-mngr/forms_efo00307/
- Official instructions and guidance: https://tax.idaho.gov/taxes/income-tax/individual-income/update-w-4/
- Edition shown on this page: Form ID W-4, EFO00307 04-28-2025 (checked 2026-09-28).
FileIt is not affiliated with or endorsed by Idaho State Tax Commission or any government. This page explains the form in general terms and is not legal, tax or immigration advice. Always read the official instructions, and check that you are using the edition the recipient accepts. Page last reviewed 2026-09-28.