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).
Revising contract law for an exam?
Get structured revision notes and timed SQE1 practice covering Offer vs invitation to treat.
Revising law for an exam?
Get the free “50 Must-Know Cases for UK Law Exams” guide — grouped by module with the ratio for each, sent to your inbox.