Asking how long a business takes to sell produces ranges wide enough to be useless, because the answer is four separate periods with different owners and very different variability. Splitting them apart is more useful than any average, because it shows which part you control, which part is genuinely unpredictable, and where an owner's own choices add or remove months. One of the four is entirely yours and it is the one most often skipped.
Clock one: preparation, which is yours
Assembling the pack, chasing what you do not hold, and getting the financial picture into a state somebody else can read. This period is invisible in most timelines because it happens before anybody counts, and it is the only one you fully control. Skipping it does not remove it; it moves the same work into diligence, where a buyer is watching the delay.
Clocks two and three: finding a buyer, and diligence
Finding a buyer has the widest range of the four and depends on the business, the sector and the route. Diligence is more predictable in shape and still elastic, because it expands to fill whatever ambiguity exists about what has been asked and answered. A tracked request list is the main thing that stops the third clock stretching.
Clock four: completion, and the things that are not yours
Between agreement and money there are consents, lender approvals, landlord approvals and the two sets of advisers. Much of this is other people's timescales and none of it compresses because you would like it to. Knowing early which third-party consents your business needs is the practical equivalent of preparation for this clock. It is also worth writing down which clock you are in when somebody asks how it is going, because the honest answer is often that three of the four have not started, and that is a very different position from being stuck.
Questions people ask about how long does it take to sell a business
Why do published averages vary so much?
Because they measure different clocks. Some count from listing, some from heads of terms, some from the owner's first thought about selling. Ask which period any figure covers before comparing it with your own.
Which clock do owners underestimate?
Preparation, followed by consents. Both involve waiting for other people and both are discoverable months in advance.
Can preparation be done while marketing?
Partly, and it is a poor trade. Being approached by a serious buyer while still assembling the pack is exactly the situation that costs momentum.