Exclusivity Agreement or Lock-out Agreement are one and the same.
Both of these are agreements where a seller promises a potential buyer not to sell the property to anyone else for a defined period. However, once that period expires, there is no obligation on the seller to sell the property and no obligation on the buyer to buy it.
There is a limited value to the agreements from a legal point of view, but they can be quite useful from a commercial or negotiating perspective.
The buyer and seller enter into the agreements in good faith. Once the exclusivity period has expired, the parties generally go on to exchange contracts, provided they have continued to show good faith.
Terms of the agreement
An exclusivity agreement can contain any terms that both parties want to put in it. It may be that the seller wants a payment in exchange for the property being taken off the market. In this case, the fee is usually non-refundable and the seller will still be under no obligation to sell the property at the end of the agreement.
The terms may require both parties to carry out certain tasks during the period, for example, the buyer may have to carry out site investigations. Or they may require both parties to progress the transaction to exchange of contracts.
It is important for both parties to understand that these terms are only of limited value as the other party cannot be forced to go through with the transaction.