Auction fees explained: buyer's premium, gate, doc and more

By Marcus Hale, Editor. Last updated September 10, 2026.

The buyer's premium is a percentage or tiered fee added on top of the hammer price. On top of that come gate, internet-bidding, documentation, late-payment and storage fees, plus sales tax and transport. Add-ons commonly run ten to twenty percent on a cheap vehicle and fall as a share of the total on an expensive one.

The fee stack

Every auction invoice starts with the hammer price, the amount your winning bid actually stopped at, and then stacks charges on top of it. The order below is roughly how the add-ons build, from the fee every platform charges to the ones that only apply if something goes wrong.

Late-payment and storage fees are missing from that stack on purpose: they are not part of a normal invoice, only a penalty for missing a deadline, and we cover them separately below. A late fee you never trigger is the cheapest fee on this page.

Not every layer applies to every sale, which is exactly why two people can buy similar vehicles on the same platform and end up with noticeably different totals. A buyer who pays by wire on time, picks the vehicle up within the free window and registers locally sees close to the minimum stack: hammer price, buyer's premium, and whatever flat fees the platform always charges. A buyer who pays by credit card, needs a week longer to arrange transport and registers a vehicle bought out of state can see nearly every layer in the diagram at once, plus a payment-method surcharge on top. The stack is the same for everyone; which layers actually get charged depends on how closely your own timeline matches the platform's.

Buyer's premium models

Platforms structure the buyer's premium in one of four ways. Knowing which model a platform uses tells you more about your total cost than the headline percentage alone, because a flat rate on a cheap lot behaves very differently from a capped rate on an expensive one.

The practical takeaway is to ask which model applies before you ever look at a listing's headline percentage. A 10% flat premium on a $3,500 car costs you $350; the same 10% on a $60,000 truck costs $6,000, and no cap softens that. A capped model does the opposite: it protects you on an expensive lot and barely matters on a cheap one, because the minimum kicks in instead.

Tiered schedules are the hardest to reason about at a glance because the rate itself changes as the price climbs, and the exact breakpoints are usually only visible once you are logged into the platform's own account. Copart's published schedule, for instance, distinguishes secured and unsecured payment methods as well as price tiers, so the same vehicle can carry two different buyer fees depending only on how you intend to pay, not on anything about the vehicle itself. That is a genuinely different structure from a simple percentage, and it is worth reading the actual fee page for a platform you plan to use regularly rather than assuming a single number applies across every lot.

None of the four models is inherently cheaper across the board; each one just shifts where the cost lands. A private buyer shopping mostly under $10,000 will usually do better under a capped or flat percentage model with a low minimum, while a buyer chasing an expensive, well-documented lot will care much more about where a cap sits than about the headline rate itself.

Fees that surprise people

Buyer's premium gets top billing because it is the biggest single line item, but the fees that actually surprise first-time buyers are almost always the smaller ones they never budgeted for. A gate fee, charged simply for taking a vehicle off the lot, applies on essentially every purchase at the platforms that use it and is easy to miss if you only priced the premium. An internet-bid fee covers the cost of bidding online rather than in person, and on some schedules it scales with the sale price the same way the buyer's premium does, so it is worth checking whether it is flat or tiered before you bid remotely on something expensive.

A documentation fee covers the paperwork the platform processes on your behalf, separate from any title-shipping charge, which is its own line item when a physical title has to be mailed rather than handed over at the counter. None of these are large individually, typically well under a hundred dollars each, but three or four of them stacked on top of a premium is where a buyer's rough mental math starts drifting from the real invoice.

The fees that hurt are the ones tied to a missed deadline. A late payment fee applies if you do not pay within the platform's stated window, which on some schedules is as short as a few business days; a storage fee then starts accruing, on some schedules per day, once you have paid but not picked the vehicle up in time. Miss both deadlines badly enough and you can trigger a relist fee, a penalty charged when you fail to complete the purchase at all and the platform puts the lot back up for sale, which on the platforms that publish one can run to a meaningful percentage of the sale price. Read the payment and pickup deadlines before you bid, not after you win; they are usually shorter than people expect, sometimes measured in single-digit days.

Finally, if a state requires a licensed dealer or broker to buy a particular title type on your behalf, that broker's own fee is a real cost of the transaction even though it never appears on the auction platform's own invoice. Ask what that arrangement costs before you assume the platform's published fees are the whole story.

Payment method itself is a fee category people tend to miss entirely. IronPlanet charges a 2.95% convenience fee for credit card payments made through its iClosing system, and Ritchie Bros charges the same 2.95% rate as a late-payment "iClosing Convenience Fee" if a wire has not cleared by its own seven-day deadline. On a $20,000 invoice, 2.95% is $590, larger than most of the flat fees on this page combined, which makes the payment method you choose, and how early you initiate it, a real line item rather than an afterthought.

Two worked examples

The two tables below apply each platform's own published buyer's-fee rule to two sale prices, so you can see how the same percentage behaves differently depending on where the fee floor or cap sits. These are simple arithmetic on each platform's stated rate, not a full invoice; gate, doc, tax and transport charges are not included here and would add further to the total, as the fee stack above shows.

The Cars & Bids row is the clearest illustration of why a floor matters: the plain 5% math on $3,500 comes to $175, but the platform's own $250 minimum overrides that, so the buyer actually owes $250, a fee that is proportionally larger than 5%. On the $25,000 car, the same 5% rate produces $1,250, comfortably between the minimum and the $7,500 cap, so the headline rate applies without adjustment. Purple Wave's flat rate needs no such adjustment at either price, which is the appeal of a flat model for a seller and the risk of one for a buyer on an expensive lot.

The Bring a Trailer row is deliberately left incomplete rather than filled in with a guess. The platform's own published terms confirm a $7,500 cap applies once a buyer's fee is charged, but the standard percentage and minimum were not visible on the pages we could verify this month, so we are not going to hand you a number we cannot stand behind. That gap is itself useful information: if a platform's standard fee is not published somewhere you can read before you bid, treat the cap as the worst case you can plan around and ask directly for the underlying rate before you commit to a maximum bid.

Sales tax and titling costs by situation

Sales tax on an auction purchase is usually collected when you title and register the vehicle, not at the auction's own checkout, and the rules genuinely vary by state: some tax the hammer price alone, some tax the hammer price plus certain add-on fees, and the applicable rate can depend on where you register rather than where the auction is held. Titling costs are a separate, usually smaller, line item: a title fee, a registration fee and sometimes a use tax if you are bringing the vehicle in from out of state. Check your state's motor vehicle agency, such as the Minnesota Department of Public Safety or your own state's equivalent, for the specific worksheet before you bid, because a buyer who only budgets for the auction invoice is routinely surprised by a tax bill that shows up weeks later at the counter.

Out-of-state purchases add one more variable: some states give a credit for sales tax already paid to another state, and some do not, so a vehicle bought at an out-of-state auction can end up taxed twice in effect if you do not check the credit rule for your home state before you commit to bidding.

Titling itself carries its own small fee stack that is easy to fold into "tax" mentally even though it is separate: a title application fee, a plate or registration fee, and in some states a weight-based or emissions-related fee that applies at first registration. None of these are auction fees in the sense this page otherwise covers, since they would apply whether you bought the vehicle at auction, from a dealer or from a private seller, but they still belong in your total-cost math because they land on the same trip to the counter as everything else.

How to compare true cost across platforms

Comparing platforms on the headline buyer's-premium percentage alone is close to useless, because a low headline rate paired with a tiered structure and several add-on fees can cost more than a higher flat rate with nothing else attached. The only comparison worth doing is an all-in one: hammer price, plus buyer's premium at your actual sale price, plus every add-on fee the platform publishes, plus your own state's tax and titling cost, plus transport if you are not picking the vehicle up yourself. We keep exactly that comparison, platform by platform and updated on the same schedule as this page, in our auction fees by platform reference table, so you do not have to rebuild the arithmetic above every time you are deciding between two listings.

A simple habit does most of the work: before you register anywhere, write down the buyer's-fee rule in one sentence, the payment deadline in days, and whether a gate or storage fee applies, then do that same exercise for the second platform you are weighing. Two platforms that look similar on price per lot often separate cleanly once you line up those three facts side by side, and the exercise takes a few minutes against a published fee page, far less time than discovering the difference after you have already won a bid.

Our view on which fees are worse than they look

None of that makes the buyer's premium unimportant; it is still the largest single number on most invoices. It just means the premium is the fee everyone already reads carefully, while the smaller, deadline-driven charges are the ones that catch people who assumed the invoice they saw at registration was the whole bill.