The EPC comes before the listing.

Under the Energy Performance of Buildings (England and Wales) Regulations 2012, a dwelling put on the market for sale needs an EPC commissioned before marketing begins, and the seller or their agent has to make it available free of charge to any prospective buyer. Failing to do so is a fixed penalty of £200 per dwelling, and more to the point, no agent will list without it.

The certificate belongs to the property, not to you. If a valid one exists on the national register from a previous sale or let, you can use it, as long as it still describes the house as it is now. A house that has since been extended, re-roofed, re-glazed or given a new heating system deserves a fresh assessment, because the old rating will undersell it.

A few buildings are exempt: places of worship, some temporary buildings, and stand-alone buildings under fifty square metres. Listed buildings are a grey area that most sellers resolve by getting one anyway; if compliance with the recommendations would unacceptably alter the building's character, that is a matter for advice, not a reason to skip the certificate.

The government's find-an-energy-certificate service lists every EPC lodged in England and Wales, searchable by postcode. Before you order one, look.

The band is on the listing, next to the price. Most buyers do not read further, so the letter does the talking. A C is a selling point in older stock and the portals let buyers filter on it. A D is unremarkable and typical of Lincoln's older houses. An E is a question at the viewing. An F or G shrinks the buyer pool, because a landlord cannot let it without works and a lender may want to know why.

The estimated energy costs on the certificate are read too, and they are calculated for a standard household rather than yours, so they can look alarming for a large old house. A buyer's surveyor will often echo the EPC's recommendations in their own report, which is one reason to do the cheap ones before you list rather than after an offer.

The assessor records what is there on the day. A box of LED bulbs fitted the week before counts; a plan to fit them does not. If you are a month from listing, these are the measures that move a band for the least money and the least mess.