Adams v Lindsell  EWHC (KB) J59, per Lord Ellenborough:
So here the defendants who have proposed by letter to sell this wool, are not to be held liable, even though it be now admitted that the answer did not come back in due course of post. Till the plaintiffs' answer was actually received, there could be no binding contract between the parties; and before then, the defendants had retracted their offer, by selling the wool to other persons.
But the Court said, that if that were so, no contract could ever be completed by the post. For if the defendants were not bound by their offer when accepted by the plaintiffs till the answer was received, then the plaintiffs ought not to be bound till after they had received the notification that the defendants had received their answer and assented to it. And so it might go on ad infinitum. The defendants must be considered in law as making, during every instant of the time their letter was travelling, the same identical offer to the plaintiffs; and then the contract is completed by the acceptance of it by the latter.
Dickinson v Dodds (1876) 2 Ch D 463, AC per James LJ:
The Plaintiff [Dickinson], being minded not to complete the bargain at that time, added this memorandum—“This offer to be left over until Friday, 9 o'clock a.m., 12th June, 1874”. That shews it was only an offer. There was no consideration given for the undertaking or promise, to whatever extent it may be considered binding, to keep the property unsold until 9 o'clock on Friday morning; but apparently Dickinson was of opinion, and probably Dodds was of the same opinion, that he (Dodds) was bound by that promise, and could not in any way withdraw from it, or retract it, until 9 o'clock on Friday morning, and this probably explains a good deal of what afterwards took place. But it is clear settled law, on one of the clearest principles of law, that this promise, being a mere nudum pactum, was not binding, and that at any moment before a complete acceptance by Dickinson of the offer, Dodds was as free as Dickinson himself. Well, that being the state of things, it is said that the only mode in which Dodds could assert that freedom was by actually and distinctly saying to Dickinson, 'Now I withdraw my offer'. It appears to me that there is neither principle nor authority for the proposition that there must be an express and actual withdrawal of the offer, or what is called a retraction.
And per Mellish LJ:
… It is admitted law that, if a man who makes an offer dies, the offer cannot be accepted after he is dead, and parting with the property has very much the same effect as the death of the owner, for it makes the performance of the offer impossible. I am clearly of opinion that, just as when a man who has made an offer dies before it is accepted it is impossible that it can then be accepted, so when once the person to whom the offer was made knows that the property has been sold to someone else, it is too late for him to accept the offer, and on that ground I am clearly of opinion that there was no binding contract for the sale of this property by Dodds to Dickinson…
Henthorn v Fraser (1892) 2 Ch 27, per Lord Herschell:
I think that a person who has made an offer must be considered as continuously making it until he has brought to the knowledge of the person to whom it was made that it is withdrawn. … The grounds upon which it has been held that the acceptance of an offer is complete when it is posted have, I think, no application to the revocation or modification of an offer. These can be no more effectual than the offer itself, unless brought to the mind of the person to whom the offer is made.
Carlill v Carbolic Smoke Ball Company  1 QB 256, per Bowen LJ:
Now, if that is the law, how are we to find out whether the person who makes the offer does intimate that notification of acceptance will not be necessary in order to constitute a binding bargain? In many cases you look to the offer itself. In many cases you extract from the character of the transaction that notification is not required, and in the advertisement cases it seems to me to follow as an inference to be drawn from the transaction itself that a person is not to notify his acceptance of the offer before he performs the condition, but that if he performs the condition notification is dispensed with. It seems to me that from the point of view of common sense no other idea could be entertained. If I advertise to the world that my dog is lost, and that anybody who brings the dog to a particular place will be paid some money, are all the police or other persons whose business it is to find lost dogs to be expected to sit down and write me a note saying that they have accepted my proposal? Why, of course, they at once look after the dog, and as soon as they find the dog they have performed the condition. The essence of the transaction is that the dog should be found, and it is not necessary under such circumstances, as it seems to me, that in order to make the contract binding there should be any notification of acceptance. It follows from the nature of the thing that the performance of the condition is sufficient acceptance without the notification of it, and a person who makes an offer in an advertisement of that kind makes an offer which must be read by the light of that common sense reflection. He does, therefore, in his offer impliedly indicate that he does not require notification of the acceptance of the offer.
R v Clarke (1927) 40 CLR 227 per Isaacs AC J at p. 235:
An offer of £100 to any person who should swim a hundred yards in the harbour on the first day of the year, would be met by voluntarily performing the feat with reference to the offer, but would not in my opinion be satisfied by a person who was accidentally or maliciously thrown overboard on that date and swam the distance simply to save his life, without any thought of the offer. The offeror might or might not feel morally impelled to give the sum in such a case, but would be under no contractual obligation to do so.
Centrovincial Estates PLC v Merchant Investors Assurance Company Ltd.  Com LR 158. Obiter dictum of Slade LJ:
Where the nature of an offer is to enter into a bilateral contract, the contract becomes binding when the offeree gives the requested promise to the promisor in the manner contemplated by the offer; the mutual promises alone will suffice to conclude the contract. In our opinion, subject to what is said below relating to consideration, it is contrary to the well established principles of contract law to suggest that the offeror under a bilateral contract can withdraw an unambiguous offer, after it has been accepted in the manner contemplated by the offer, merely because he has made a mistake which the offeree neither knew nor could reasonably have known at the time when he accepted it.
Interfoto Picture Library Ltd v Stiletto Visual Programmes Ltd  QB 433, per Lord Denning MR:
The customer pays his money and gets a ticket. He cannot refuse it. He cannot get his money back. He may protest to the machine, even swear at it. But it will remain unmoved. He is committed beyond recall. He was committed at the very moment when he put his money into the machine. The contract was concluded at that time. It can be translated into offer and acceptance in this way: the offer is made when the proprietor of the machine holds it out as being ready to receive the money. The acceptance takes place when the customer puts his money into the slot. The terms of the offer are contained in the notice placed on or near the machine stating what is offered for the money. The customer is bound by those terms as long as they are sufficiently brought to his notice beforehand, but not otherwise. He is not bound by the terms printed on the ticket if they differ from the notice, because the ticket comes too late. The contract has already been made.
Shogun Finance Ltd v Hudson  1 AC 919, per Lord Millett (in his dissenting judgment) at p.949:
 It is trite law, …, that before a contract can come into existence there must be offer and acceptance, and these must correspond. The offer must be addressed to the offeree, either as an individual or as a member of a class or of the public. The acceptance must come from one who is so addressed and must itself be addressed to the offeror. It is not possible in law for a person to accept an offer made to someone else; or to intercept an acceptance of someone else’s offer and treat it as an acceptance of his own.
 This is usually straightforward enough, at least in the absence of fraud.
and per Lord Walker of Gestingthorpe at para 188:
Where there is an alleged contract reached by correspondence, offer and acceptance must be found, if they are to be found at all, in the terms of the documents.