For nearly every private seller: no. The loss is not deductible, the sales tax is the buyer’s at titling, and five states charge nothing at all. Here is the whole answer, sourced.

A personal car is a capital asset to the IRS, and its rule cuts one way. Sell for more than you paid — rare outside collectibles and the 2021–22 market — and the gain is a taxable capital gain you report. Sell for less, which is nearly everyone, and the loss is not deductible: IRS Publication 544 lists “a car used for pleasure or commuting” among personal-use assets and says of them, verbatim, “Loss from the sale or exchange of that property is not deductible.” So the typical private seller owes the IRS nothing and gets nothing — no form, no deduction, no event.
Sales tax on a private-party sale is real money, but it is the buyer’s money: in every state that taxes the transaction at all, the buyer self-assesses use tax at titling, paid to the county treasurer or DMV — never collected by you at the kerb. Kansas says it in one sentence: “The seller is not responsible for collecting, reporting and remitting” the tax; the buyer pays it when registering. We looked for a state that puts a collection duty on a private seller and found none — and two (Arizona, Nevada) exempt casual private-party sales from the tax entirely.
| State | What its own pages say |
|---|---|
| Alaska | No statewide sales or use tax exists to charge on a vehicle sale. … ↗ |
| Delaware | No sales tax; instead Delaware Code Title 30 section 3002 imposes a Motor Vehicle Document Fee 'paid by the owner' at titling, currently 5.25% of purchase price… ↗ |
| Montana | Montana Dept. of Revenue states plainly: 'Montana does not have a general-use sales tax.' This is the same reason Montana LLC vehicle-registration arrangements exist — there is no sales/use tax event to trigger on an in-state vehicle purchase. … ↗ |
| New Hampshire | New Hampshire has no general sales tax and no use tax. … ↗ |
| Oregon | Oregon has no general sales tax, and its two narrow vehicle taxes both exclude an ordinary private-party sale within the state. … ↗ |
Price the car knowing the buyer is doing use-tax arithmetic on top of your number — in most states several hundred dollars they will pay at the counter, not to you. Keep the bill of sale: the buyer’s tax is usually assessed on the stated price, and a lowballed figure on paper is the classic audit flag that lands on both parties. And if you genuinely sold at a gain, the gain goes on Schedule D — the one case where the IRS is interested in your driveway sale.
Citing this page. The two sentences worth borrowing — losses on a personal car are not deductible, and no state makes a private seller collect sales tax — each trace to the primary texts above; quote them with those links or this page, which keeps the full trail.
Related: the transfer fees that ARE the seller’s · the bill of sale that protects both parties’ tax story.
Tax law changes by legislature and by year; the linked IRS publication and state pages are the current record, and a seller with a genuine gain or a business-use car is outside this page’s ordinary case and inside an accountant’s.