What is a buyer's premium?
A buyer's premium is a fee charged by the auction house on top of the hammer price (the amount you actually bid and won the item for). It's how most auction houses make their money, separate from any commission they charge the seller. It's usually shown as a percentage — commonly somewhere between 10% and 25% depending on the auction house.
Do I pay VAT on top of the buyer's premium?
In most cases, yes. UK auction houses typically charge VAT on the buyer's premium itself (not usually on the hammer price, unless the seller is VAT-registered and the item is sold under specific VAT schemes). This is why the total cost of a bid is often higher than people expect — it's hammer price + buyer's premium + VAT on that premium, not just the hammer price and premium alone.
Why is there an extra fee for bidding online?
Many UK auction houses charge an additional online bidding surcharge — commonly 3–5% — on top of the standard buyer's premium, specifically for bids placed through an online bidding platform (like the-saleroom.com or easyliveauction) rather than in person, by phone, or as an absentee bid. It's worth checking the specific auction house's terms, since this fee catches a lot of bidders out.
How do I work out the total cost of my bid?
Add up: hammer price (your winning bid) + buyer's premium + VAT on the premium (and on the bid itself, if applicable) + any online bidding surcharge + delivery or collection costs. Our auction fee calculator does this automatically — just enter your bid and the auction house's fee percentages.
Can I calculate the maximum I can bid on a fixed budget?
Yes — switch to "I have a budget" mode on the calculator. Enter your total spending limit and it works backward through the buyer's premium, VAT, and any online fee to tell you the maximum hammer price you can actually afford to bid up to.
Does the calculator support currencies other than GBP?
Yes — the calculator supports GBP, USD, EUR, JPY, and AUD, with a live currency conversion feature so you can see the equivalent cost in another currency using current exchange rates.
I'm bidding on several lots — can I track a running total?
Yes — after calculating a lot's total, tap "Add this lot to my list" to save it to a running list. You can rename each lot, expand any entry to see its full breakdown, and see a combined running total across everything you've added.
Is this calculator accurate?
The maths is accurate based on the figures you enter, but it's only as accurate as those figures — every auction house sets its own buyer's premium, VAT treatment, and online fees, and these can vary or change. Always confirm the exact terms with the auction house or seller before paying, particularly for high-value bids.
Does this cost anything to use?
No — the calculator is free to use, with no account or sign-up required. See our Privacy Policy for details on how the site works.