A trade-in is two prices pretending to be one

The points below about part exchange arithmetic are ordered by how much difference they make, not by how often they get repeated.

Two transactions in one envelope

A part-exchange combines what you pay for the new item and what you receive for the old one into a single net figure. That figure can be reached by many combinations, and most of them are invisible once the two halves have been added together. A seller can therefore offer a striking amount for your old item while quietly holding firm on the new one.

The net outcome may be identical to a modest trade-in and a keener price, but only one version sounds generous. Separating the two numbers before agreeing anything is the whole of the technique and it takes one question.

Asking the question that unbundles it

Ask what the price of the new item would be if you were not trading anything in at all. Then ask what they would pay for your old item as a straightforward purchase with no other transaction attached. Where a seller declines to separate them, that reluctance is itself informative about where the value sits.

Per unit, some sellers genuinely cannot separate them, because a manufacturer promotion may require the trade-in to exist. Even then, knowing the standalone price lets you compare the whole package against buying and selling separately.

What a trade-in is really selling

The product being sold is convenience, and convenience in a private sale is worth a genuine and sometimes substantial amount. You avoid listing, photographing, answering questions, meeting strangers, handling payment and dealing with any later complaint. You also avoid the risk of a buyer disputing the transaction afterwards, which is a real cost that people underestimate.

The number underneath says something else: valuing that convenience honestly, in money rather than in principle, is the difference between a sensible decision and a resentful one. If the gap between trade-in and private sale is small, the trade-in is straightforwardly the better outcome.

Where trade-in valuations come from

The figure offered is based on what the seller expects to get for your item after refurbishment, warranty and the cost of handling it. That is necessarily below what a private buyer would pay, because a business is taking on risk and doing work you would otherwise do.

At the till, condition grading is where most disputes arise, since the description you give and the assessment they make can differ. Where a valuation is given remotely and confirmed on arrival, the initial figure is an estimate rather than an offer. Read what happens if the assessment comes back lower, because getting the item returned can be slow and occasionally costs money.

Data, accounts and the things attached to your old item

Before any trade-in, remove personal data, sign out of accounts and unlink the device from anything it is registered to. Items still linked to an account can be unusable for the next owner, which sometimes results in the trade-in being reversed.

Keep any accessories you were not required to send, since they frequently add nothing to the valuation and are worth keeping. Photograph the item and its condition before sending it, because that record is what settles a disagreement about grading. Get written confirmation of what was received and in what condition, since a paper trail is the only leverage available afterwards.

Retailers vary discounting by region and by account, so the price on your screen may differ from any quoted here.

Comparing the whole package properly

Work out the total cash leaving your household under each route, including any listing fees, postage and the value of your time. Compare that against completed private sale prices for your item in its actual condition rather than in the condition you remember.

Include the delay, because money from a private sale arrives at an unknown time and a trade-in settles immediately. Where the numbers are close, take the simpler route, since the difference will not survive an hour of messaging with strangers. Where the gap is wide, the private sale is worth the work, and knowing that requires having separated the numbers first.

Everything above, in order of what to do first

1. Two transactions in one envelope. A part-exchange combines what you pay for the new item and what you receive for the old one into a single net figure.
2. Asking the question that unbundles it. Ask what the price of the new item would be if you were not trading anything in at all.
3. What a trade-in is really selling. The product being sold is convenience, and convenience in a private sale is worth a genuine and sometimes substantial amount.
4. Where trade-in valuations come from. The figure offered is based on what the seller expects to get for your item after refurbishment, warranty and the cost of handling it.
5. Data, accounts and the things attached to your old item. Before any trade-in, remove personal data, sign out of accounts and unlink the device from anything it is registered to.
6. Comparing the whole package properly. Work out the total cash leaving your household under each route, including any listing fees, postage and the value of your time.

The takeaway

Ask for both numbers separately, because a single net figure can be reached in many ways and only one of them favours you.

Decide what you would pay before you look at what they are asking.