How to fill out Idaho ST-133

Not a Transportation Department form at all - this one belongs to the Idaho State Tax Commission, and it is the reason a car sold to your own daughter costs her nothing in tax while the same car sold to a neighbour costs 6%. The Tax Commission's instruction to the seller is direct: sign the Seller's section of Form ST-133 and give it to your relative, who needs a completed copy when they register the vehicle. The same sheet carries a second, quite separate exemption for a sale delivered to an enrolled tribal member within the boundaries of a reservation, and by signing you are certifying that the delivery took place there.

Written against ST-133 (EFO00196 07-21-2023), issued under Idaho Code 63-3622K and Idaho Sales and Use Tax Administrative Rules 091 and 107. This is the family SALE certificate. If no money is changing hands at all, the form is a different one - ST-133GT, the Gift Transfer Affidavit - and the two are not interchangeable, because the gift version disqualifies itself the moment anything of value moves in either direction.

Two documents, and they are not the same thing. Take the blank ST-133 from the tax.idaho.gov copy so you get the revision that is current today, then print our ST-133 guide and keep it beside you while you fill theirs in.

Step 1 · the form itself Blank ST-133 — Sales Tax Exemption Certificate, Family or American Indian Sales PDF at tax.idaho.gov · new tab Step 2 · how to fill it in Our filled-in ST-133 guide PDF · print and keep beside you

Filled in

What a completed one looks like

This is the actual ST-133, rendered from the PDF the Idaho Transportation Department, Division of Motor Vehicles publishes and completed end to end: letterhead, every field, and the blocks at the foot.

Amber — you write it
Grey — not yours to fill
Numbered — explained below

Idaho Form ST-133, Sales Tax Exemption Certificate for family sales, filled in for a 2009 Honda CR-V, vehicle identification number 5J6RE48369L024176, sold by Curtis A. Yarnell of Pocatello to his daughter Annelise R. Yarnell of Chubbuck, with all three family questions answered yes and the parent/child box marked. — The American Indian exemption block in the lower half is washed grey because it is a separate exemption on the same sheet, used instead of the family questions rather than alongside them. Both signature rules are used - the Tax Commission asks the seller to sign this one and hand it over.

Field by field

Every line, in the order you meet it

1
You fill this in
Check the relationship against the list
Parent and child, grandparent and grandchild, brother and sister. That is the entire list.
Watch out: It is worth checking before you agree a price. Outside those three, the buyer owes 6% of whatever the two of you write down.
2
You fill this in
Check that you paid tax on it yourself
Question 2 asks whether the seller paid sales tax when acquiring the vehicle.
Watch out: Your old registration or title paperwork is where the answer lives. The Tax Commission's recordkeeping page tells a family seller to keep exactly those documents.
3
You fill this in
Fill in both columns and the vehicle rule
Buyer left, seller right, then year, make, model and VIN across the middle.
Watch out: Copy the VIN off the certificate. This sheet has to line up with the title application it travels with.
4
You fill this in
Answer the three questions and mark the relationship
Yes to all three, then tick Parent/child, Grandparent/grandchild or Brother/sister.
Watch out: Leaving the relationship box unticked is the most common way this sheet comes back - the yes on its own does not say which relationship.
5
You fill this in
Sign the seller's side
Signature, date, phone number and driver's licence number with its state of issue.
Watch out: The Tax Commission's instruction is to sign it and give it to your relative. It is no use to them unsigned, and they cannot sign it for you.
6
You fill this in
Still sign the title over properly
The exemption certificate replaces the tax, not the transfer. The certificate of title is assigned exactly as in any other sale.
Watch out: And still file your release of liability within five days. A family sale is a sale for every purpose except the 6%.

At a glance

What goes where

On the form	What to put in it
Buyer's name, Address, City, State, ZIP Code	The left-hand column. In a family sale this is the relative receiving the vehicle.
Seller's name, Address, City, State, ZIP Code	The right-hand column, and the half the Tax Commission tells the seller to sign.
Vehicle/Vessel Year, Make, Model, Hull or Vehicle Identification Number	One rule of four boxes describing what is moving.
Family Sale question 1 - Is the vehicle being sold a qualifying motor vehicle?	Yes or no. The block above it excludes vessels, ATVs, UTVs, SOHVs, off-road motorcycles, snowmobiles and trailers by name.
Family Sale question 2 - Did the seller pay sales tax when acquiring the motor vehicle?	Yes or no. This is the question that most often ends the exemption, and it is about you rather than about the buyer.
Family Sale question 3 - Is there a qualifying family relationship between the buyer and seller?	Yes or no, and if yes, one of three boxes: Parent/child, Grandparent/grandchild, Brother/sister.
American Indian Exemption - reservation name, tribe name, tribal identification number	Three fill-in rules belonging to the second exemption on the sheet, used instead of the family block rather than as well as it.
Buyer's signature and Date; Seller's signature and Date	Two signature rules side by side, under a certification that the statements on the form are true and correct and that false information can result in criminal and civil penalties.
Buyer's phone number and Seller's phone number	One each.
Driver's license number and state of issue or taxpayer ID, for each of you	The identifier boxes at the foot of each column.

What gets this one rejected

•A no to any of the three family questions. The form stops you itself: if you answered no to any of the above questions, STOP, you don't qualify for this exemption.
•A relationship outside the three listed. Parent and child, grandparent and grandchild, brother and sister. Aunts, cousins, in-laws and spouses are not on the list.
•A trailer, a boat, an ATV, a UTV, an off-road motorcycle or a snowmobile. The family exemption applies only to motor vehicles, and the form names every excluded category.
•A seller who never paid tax on the vehicle themselves. Question 2 asks it directly and the Tax Commission's exemption pages repeat the requirement.
•Sending it to the Tax Commission. It goes to the county assessor's motor vehicle office with the title application - the form says to provide the completed form to the county assessor (DMV) when titling or registering.

Rules that decide whether it is accepted

•Community property widens it slightly. The form's own note: a motor vehicle that is community property may be sold to a qualifying family member of either spouse.
•A seller who cannot sign can write instead. The Tax Commission allows it in one line - a seller who is unable to sign this form can provide a letter stating they sold the motor vehicle to a qualified family member.

Every line here was read off ST-133 (EFO00196 07-21-2023) itself — the PDF is here — and off the Idaho Transportation Department, Division of Motor Vehicles pages. This is plain-language help with a form, not legal advice, and where our wording and the agency's differ, theirs governs.

Back to all Idaho seller paperwork, or what selling a car in Idaho involves.

How to fill out Idaho ST-133

What a completed one looks like

Every line, in the order you meet it

Check the relationship against the list

Check that you paid tax on it yourself

Fill in both columns and the vehicle rule

Answer the three questions and mark the relationship

Sign the seller's side

Still sign the title over properly

What goes where

What gets this one rejected

Rules that decide whether it is accepted

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