ZOPA in Negotiation: The Zone of Possible Agreement Explained

Every negotiation has limits. The buyer will not pay more than a certain amount; the seller will not accept less than a certain amount. Whether a deal is possible at all depends on whether those limits overlap.

ZOPA stands for zone of possible agreement: the range between the buyer’s and the seller’s walk-away points. An agreement is only possible inside this range. In multi-issue B2B negotiations, each variable has its own ZOPA.

What does ZOPA mean in negotiation?

Each party has a walk-away point (WAP): the point at which it leaves the negotiation rather than accept a worse deal. It is also called the reservation price or resistance point. For a buyer, it is the highest price it will pay; for a seller, the lowest price it will accept. When the buyer’s walk-away point is higher than the seller’s, the range between them is the ZOPA.

ZOPA example: a single-price negotiation

In this illustrative example, a buyer is prepared to pay up to 12 per unit and a seller will accept no less than 8. The ZOPA runs from 8 to 12. Both parties open outside it: the seller asks 15, the buyer offers 5. These extreme openings create room to move, and where the deal finally lands between 8 and 12 depends on preparation, information and the way each side makes its moves.

ZOPA vs BATNA

BATNA stands for best alternative to a negotiated agreement, a term popularised by Roger Fisher and William Ury in Getting to Yes. Your BATNA is what you will do if this negotiation fails, and it should set your walk-away point: you walk away when the deal on the table is worse than your best alternative. The ZOPA is then the overlap between both parties’ walk-away points. A stronger alternative moves your walk-away point in your favour and strengthens your position.

What if there is no ZOPA?

If the buyer’s limit is below the seller’s, no agreement is possible on that single variable. Before you walk away, consider these options:

• Add variables. Trade-offs on timing, payment terms, scope or risk allocation can create a ZOPA where none existed. This is the core of integrative negotiation.
• Test your assumptions. Your estimate of the other party’s walk-away point may be wrong.
• Revisit your alternatives. A change in either party’s BATNA changes the walk-away points.
• Walk away. No deal is better than a deal worse than your alternative.

ZOPA in multi-variable B2B negotiations

Most textbook examples use a single price. Real B2B deals involve price, volume, payment terms, contract length, service levels and more. Each variable has its own range between your worst acceptable and your best possible outcome. Mapping them one by one shows where you have room, and where the other party may value something more than you do. The illustrative move planner below shows a supplier’s view.

With this view, a price that would sit outside the ZOPA on its own may become acceptable when it comes with higher volume or shorter payment terms. That is how trading across variables creates room for agreement.

How to work inside the ZOPA: plan your moves

• Set your opening per variable, ambitious but credible, and outside the range you expect to settle in.
• Plan the size, sequence and timing of each move in advance instead of improvising at the table.
• Make decreasing concessions, so the other party sees you are approaching your limit.
• Link every concession to something in return: “If you…, then we…”.
• Treat the other party’s walk-away point as an assumption to test during the negotiation, not a fact.

How the ZOPA behaves across the IMPACT Negotiation Gauge

The IMPACT Negotiation Gauge describes four types of negotiation. The ZOPA plays a different role in each:

• Auction: the auctioning party uses competition between bidders to push offers towards their walk-away points.
• Value distribution: there is usually one dominant variable and one ZOPA. The task is to claim as much of that zone as possible.
• Value enhancement: several variables each have their own ZOPA. Trading across them can make a deal possible that no single variable would allow.
• Value creation: by sharing interests and developing new options together, the parties can change what each is willing to accept and open up new room for agreement.

Read more about the four types in our guide to the types of negotiation.

How to estimate the other party’s walk-away point

The other side will rarely tell you its limit. You can build an informed estimate from:

• Their alternatives: who else could they buy from or sell to, and at what cost?
• Their pressures: are they under pressure to grow or to cut costs, and how important is this deal to them?
• Their deadlines and authority: what can the person across the table decide alone?
• Their language: phrases such as “I was thinking of…” or “around…” often signal room to move.
• Their reactions: how they respond to your proposals tells you how close you are to their limit.

Frequently asked questions

What does ZOPA stand for?

ZOPA stands for zone of possible agreement: the range between the parties’ walk-away points within which a deal can be made.

What is the difference between ZOPA and BATNA?

Your BATNA is your best alternative if the negotiation fails, and it determines your walk-away point. The ZOPA is the overlap between both parties’ walk-away points.

Can a ZOPA be expanded?

Yes. Introducing variables that the parties value differently and trading them can expand the ZOPA, or create one where none existed on price alone.

Put the ZOPA to work in your next negotiation

In our training programmes, participants build a ZOPA per variable and a move planner for real deals, then test them in simulations against experienced negotiators.

Explore our negotiation training