The short version
A buyer's premium is a percentage (commonly 5 to 10 percent) added to your winning bid and paid by you, the buyer, at closing. It is part of the total purchase price, so you factor it into your maximum bid before auction day. If you want to pay no more than $100,000 total and the premium is 10 percent, your maximum hammer bid is about $90,900.
Definition
A buyer's premium is an additional amount, usually stated as a percentage of the hammer (winning) bid, that the buyer agrees to pay on top of that bid. The premium is disclosed in the auction's published terms before registration.
How it is calculated
On most residential auctions the premium is a straight percentage of the hammer price:
- Hammer price: $150,000
- Buyer's premium: 10%
- Total purchase price: $150,000 + $15,000 = $165,000
Some auctions use a flat fee or a tiered structure. The published terms will always specify the exact calculation.
Why it exists
The buyer's premium funds the work that makes a professional auction possible:
- Professional photography, drone, video, and marketing.
- MLS entry, digital advertising, targeted buyer outreach.
- Bidder registration, buyer qualification, platform hosting.
- Transaction management, contract execution, closing coordination.
- Compliance, licensing, and insurance costs.
The seller can list at auction with modest out-of-pocket cost because the buyer's premium funds the process. In effect, the premium is baked into what the market is willing to pay for the property.
A real example
Say a property is offered with a 7 percent buyer's premium:
- You bid $200,000 and win.
- Premium: 7% of $200,000 = $14,000.
- Total purchase price: $214,000.
- Earnest money: see the auction terms and conditions.
- Balance due at closing: $214,000 minus earnest money and any deposit.
Factoring it into your bid
Serious buyers set their maximum by all-in cost, not by hammer. Here is the working formula when you know the maximum you can pay:
- Maximum you can pay all-in: $250,000
- Premium rate: 7% (multiplier 1.07)
- Maximum hammer bid: $250,000 ÷ 1.07 = $233,644
- Any bid above $233,644 pushes your all-in cost past $250,000.
Write your maximum hammer number down before auction day. Do not recalculate in the heat of live bidding.
Common rates
Residential real estate auctions in the U.S. commonly carry buyer's premiums between 5 and 10 percent, with 10 percent being most common for competitive online auctions. Commercial and specialty auctions sometimes use different structures. Check the specific terms for each auction.
Is the buyer's premium negotiable?
In real estate auctions, no. The premium is a published term that applies uniformly to every registered bidder. Uniform terms are part of what keeps the process fair.
Tax implications
The buyer's premium is generally included in your cost basis on acquisition, which affects depreciation (for rentals) and capital gains (on eventual sale). Consult your accountant for advice specific to your situation.
Buyer's premium vs. realtor commission
On a traditional sale the seller typically pays commission to both the listing and selling brokers, and that commission is priced into the number the seller accepts. On an auction the buyer's premium is paid by the buyer at closing. The economic effect is similar: transaction costs are part of the total price. The visibility is different, and the premium's mechanics let sellers and auction firms invest more heavily in marketing without out-of-pocket exposure to the seller.
Calculating your true acquisition cost
A full acquisition math for a financed buyer:
- Hammer price + buyer's premium = total purchase price.
- Total purchase price + closing costs (title, transfer, prorations) = cash to close before financing.
- Subtract loan amount to arrive at down payment and cash at closing.
For the mechanics of getting financing set up for an auction purchase, see can I finance an auction purchase.
Pro tips for bidders
- Set your maximum by all-in cost, then work backward to a hammer bid before auction day.
- Write the hammer number down and do not change it once bidding starts.
- Add closing costs, escrow, and any transfer fees on top of the premium, not just the premium itself.
- Confirm whether the premium is a percentage or flat fee, and whether it is capped.
- Review the auction terms before you register so the premium is not a surprise.
For a deeper look at how the premium affects your exit math, read Flip vs. Hold: Auction Edition. For a fast underwriting framework, see Underwriting an Auction Deal in 20 Minutes.
Frequently asked questions
Is the buyer's premium negotiable?
In real estate auctions, the buyer's premium is set in the published terms and is not negotiable per buyer. Every registered bidder pays the same rate on their winning bid.
Is the premium included in my tax basis?
Yes. The buyer's premium is generally included in your cost basis at acquisition, which affects depreciation for rentals and capital gains on eventual sale. Talk to your accountant for advice specific to your situation.
How do I factor the premium into my max bid?
Divide your maximum all-in price by one plus the premium rate. If you can pay $100,000 total and the premium is 5%, your maximum hammer bid is $100,000 divided by 1.05, or about $95,238.
Can I pay the hammer price without the premium?
No. The buyer's premium is part of the total purchase price you agree to pay when you register and bid. It is not optional and cannot be removed after you win.
Why do auctions charge a premium instead of just asking a higher price?
The premium is disclosed upfront and applies uniformly, which keeps bidding transparent. It also funds marketing, platform costs, and transaction management so sellers can list with lower out-of-pocket expense.