Search for an average cost of selling and you will be given a single figure, usually a four digit one, presented as though it were a fact about the country. It is not a useful number, and this page explains why rather than adding another one. The largest line on the sheet is a percentage of a sale price under a contract you have not signed, so an average buries the two things that actually decide your total.
An average hides the two variables that matter
A commission is a share of the sale price, so the fee on a house at one price and a house at twice that price differ by a factor of two before anyone has negotiated anything. And the rate itself is contractual: the Estate Agents Act 1979 requires the agent to tell you the amount of their remuneration before you enter the contract, which means the rate is a thing you agree rather than a thing the market fixes. Average those two together across every sale in the country and the result describes no particular seller at all.
What genuinely does not vary much
The fixed lines are the ones an average would describe reasonably well, and they are the small ones. Conveyancing sits in a band set mostly by tenure and by whether there is a mortgage to redeem. The EPC is a one off that lasts ten years and is required before you market. Removals scale with volume and distance rather than with the price of the house. If you want a rule of thumb for the small lines, these are the three to hold roughly constant while you vary the fee and the price.
What to work out instead
Take the price your agent is advising you to ask, put the fee they have quoted next to it in whichever form they quoted it, settle the VAT question, add the three fixed lines, and subtract the mortgage you are redeeming. That produces a number about your house rather than about the country, and it takes about a minute. Then run it again at the price you would accept rather than the price you are asking. The difference between those two answers is the useful output, because it is the part of your plan that depends on the negotiation.
Questions people ask about cost of selling a property
Why do published averages differ so much from each other?
Because they average different things: different price bands, different fee models, and sometimes the buyer's costs folded in with the seller's. Read what a figure covers before you use it.
Is a percentage rule of thumb any better?
Slightly, for the fee alone, and not at all for the total, because the fixed lines do not scale with the price and dominate at the bottom of the market.
What if I have not chosen an agent yet?
Run the sheet with the fee left at zero first. That gives you the floor of your costs, and every quote you then collect can be added to it one at a time.