Contract law
Offer vs invitation to treat
An offer is a clear statement of terms the offeror is prepared to be bound by the moment it is accepted; an invitation to treat is merely an invitation for others to make offers. The distinction decides who is the offeror and when a binding contract forms.
Last reviewed 14 June 2026
| Aspect | Offer | Invitation to treat |
|---|---|---|
| Legal effect | Can be accepted to form a binding contract | Cannot be accepted — it only invites offers |
| Typical examples | A unilateral promise to pay on performance (Carlill) | Shop displays (Boots), shop windows (Fisher v Bell), most adverts (Partridge v Crittenden) |
| Who makes the offer | The offeror | The other party — e.g. the customer at the till |
| Why it matters | Acceptance forms the contract immediately | The “seller” can still refuse the customer's offer |
Key cases
- Pharmaceutical Society of Great Britain v Boots Cash Chemists [1953] 1 QB 401
- Fisher v Bell [1961] 1 QB 394
- Partridge v Crittenden [1968] 1 WLR 1204
Frequently asked questions
What is the difference between an offer and an invitation to treat?
An offer can be accepted to create a contract; an invitation to treat (a shop display, advert or shelf) only invites others to make offers (Pharmaceutical Society v Boots).
Is an advertisement an offer?
Usually it is an invitation to treat (Partridge v Crittenden), unless it is a unilateral offer promising to pay on performance (Carlill v Carbolic Smoke Ball).