Negotiation glossary
What is ZOPA?
Updated 8 October 2026 · 2 min read
The ZOPA (Zone Of Possible Agreement) is the overlap between what one side is willing to accept at most and what the other side is willing to accept at least. Every deal that will ever be signed lies inside it; when the two limits do not overlap, there is nothing to negotiate about.
Picture a used car. The seller will not go below 8,000 euros; the buyer will not go above 9,500. The ZOPA is the 1,500 euros between those two numbers, and the whole negotiation is a fight over where inside that range the deal lands. Neither side knows the other's limit, which is what makes the exercise interesting.
What you can and cannot know
You know your own reservation price. You can only estimate the other side's, from their BATNA, their behaviour and the market. That asymmetry has two practical consequences:
- Do not reveal your limit. Once the other side knows your maximum, the ZOPA collapses to a single point: their preferred edge of it
- Probe for theirs. Questions like "what would make this a yes for you?" or "what did the last buyer offer?" narrow your estimate without giving yours away
Positional versus value-creating
In a one-issue negotiation (price only), the ZOPA is a line and every euro you gain is a euro they lose. This is distributive negotiation. When you add issues (delivery date, payment terms, scope, warranty), the zone becomes a surface and trades appear: you give on what costs you little and matters to them, and vice versa. That is integrative negotiation, and it is how experienced negotiators create a ZOPA where none seemed to exist.
A common mistake
Treating the midpoint of the ZOPA as the "fair" outcome. The midpoint depends entirely on where the two limits sit, and the other side has every incentive to overstate theirs. Fairness lives in the arguments (comparable prices, costs, alternatives), not in arithmetic on two numbers you cannot verify.
A ZOPA in numbers
A seller will accept anything above 280,000 euros for an apartment; a buyer will pay up to 295,000. The ZOPA runs from 280,000 to 295,000: every price inside it beats both parties' alternatives. Where the deal lands inside those 15,000 euros depends on the anchors, the concessions and the information each side gives away.
| Seller | Buyer | |
|---|---|---|
| BATNA | Another buyer interested at 275,000, with a later date | A similar flat at 285,000, further from work |
| Reservation price | 280,000 (minimum) | 295,000 (maximum) |
| Opening offer | 310,000 | 265,000 |
| ZOPA | 280,000 to 295,000 | 280,000 to 295,000 |
The term comes from Howard Raiffa's work on negotiation analysis (The Art and Science of Negotiation, 1982), which built the zone from the two reservation values.
Negosim scenarios each hide a counterpart limit you have to discover; the analysis tells you afterwards how close you got to it.
Related terms
- Reservation price: Your reservation price is the least favourable terms you will accept before you prefer your best alternative (your BATNA). For a seller it is a minimum, for a buyer a maximum; it is the one number to fix before a negotiation and never to reveal during it.
- BATNA: Your BATNA (Best Alternative To a Negotiated Agreement) is the best option you already have if this negotiation ends without a deal. Any agreement worse than your BATNA should be refused; any agreement better than it is worth considering.
- Anchoring: Anchoring is the effect the first figure named in a negotiation has on the final result. Both sides adjust from that figure rather than from an objective value, so the party that opens with a credible, ambitious number tends to close nearer to it.
- Bargaining power: Bargaining power is your ability to get the terms you want in a negotiation. It comes mostly from how good your alternatives are compared with the other side's, how much time pressure each side faces and how much each side knows; it is relative, not a fixed trait of a person or a company.
