You've found something in the loft.

Perhaps it's a collection inherited from a relative.

An old watch.

Coins.

Stamps.

A painting.

Something you've spent 15 years walking around in the spare bedroom.

An auctioneer thinks it's saleable.

Then auction day arrives and the hammer finally falls:

£500.

Excellent.

So £500 is coming your way?

Not necessarily.

Hammer price isn't take-home price

Auction houses can charge sellers in different ways.

There may be:

seller's commission
VAT on the commission
minimum commission
lotting or entry charges
photography or online charges
insurance or collection costs

Not every auctioneer charges all of these, which is precisely why the percentage alone doesn't tell you enough.

And we've found a local example where we can actually show the calculation.

A real Ely example

Cambridgeshire Philatelic Auctions in Ely publishes its vendor charges.

For sales up to £500, its published seller's commission is 17.5%, plus VAT, with a minimum commission of £3 per lot plus VAT.

So let's say your stamps sell for exactly £500.

Hammer price: £500

17.5% seller's commission = £87.50

VAT at 20% on that commission = £17.50

Total commission including VAT = £105

That leaves approximately:

£395

before any other applicable costs.

So:

£500 sold ≠ £500 received.

And that isn't necessarily a bad deal.

What are you paying the auctioneer to do?

This is the other half of the calculation.

An auctioneer isn't simply taking your item, putting it on a table and keeping £105.

Depending on the auction house and item, the service can involve:

valuation and specialist knowledge

cataloguing and description

photography

marketing

access to an established pool of bidders

handling enquiries

running the auction

collecting the buyer's money

administration after the sale

And, importantly, competition between bidders.

An item you might have sold privately for £300 could conceivably achieve considerably more when the right buyers compete for it.

Equally, there is no guarantee it will.

That's auction.

Here's the question I'd ask

Don't ask only:

“What percentage do you charge?”

Ask:

“If this sells for £500, approximately how much will I receive after every seller charge?”

That's much harder to misunderstand.

What about the buyer?

Here's another wrinkle.

The winning bidder can also pay more than the hammer price.

The same Ely auctioneer currently publishes a 12.5% buyer's premium plus VAT.

So the seller can receive less than £500 while the buyer pays more than £500.

They're paying different charges for different sides of the transaction.

Auction isn't automatically the best answer

Before consigning something, consider the alternatives.

Private sale

Potentially more money stays with you, but you find the buyer, advertise it, answer messages, negotiate and deal with payment/collection yourself.

Online marketplace

Potentially enormous audience, but fees, postage, returns, fraud risk and the work involved vary enormously by platform and item.

Specialist dealer

Potentially fast and straightforward, but the dealer needs room to resell at a profit.

Auction

You gain expertise, marketing and competitive bidding — but you pay for the service and don't know the final price beforehand.

The right route can depend enormously on what you're selling.

The £500 Test

Before choosing an auction house, ask for five numbers:

1. Seller's commission

2. VAT

3. Lotting or entry fee

4. Any other seller charges

5. Your estimated net proceeds if the item hits its valuation

Then you can compare like with like.

Because:

“We think it could make £500”

and

“You'll receive about £395 if it makes £500”

are two quite different pieces of information.

One final question

Have something sitting at home that you've always wondered about?

Don't start by asking:

“How much is it worth?”

Try:

“What might it sell for — and what would I actually receive?”

That's the number that matters.