Overage can be secured in many different ways, but some are more effective than others.

In practice, imposing a restriction on the title to the property at the LR is the most common method. This will normally say that no disposition (eg long lease) of the land can take place unless the new owner has entered into a deed of covenant with the seller, promising to make the payment. This then ensures that there is always a direct contractual commitment from the relevant owner from time to time. However, there are alternative mechanisms that can be used:

imposing a charge over the title to the property. That charge will not secure anything until the trigger happens, but when it does the landowner may be able to take possession and/or force a sale to recover the payments due. But, a charge is unlikely to be acceptable to either the developer or its funder;

rights of re-entry are sometimes reserved to procure enforcement of a positive covenant to pay overage. These are probably enforceable, but are subject to the exercise of the court’s inherent power to grant relieve against forfeiture. But, few well-advised buyers would allow themselves to submit to a right of re-entry, and it is usually regarded as an unacceptable fetter on the land;

a bank or insurance bond may be supplied. In practice, a buyer may object to the cost of this;

a restrictive covenant, with provision for the release of the restriction on payment of the overage, is another possibility. But, this is not effective if the seller retains no land that can benefit from the restriction. Plus, there is always the danger that the Lands Tribunal might vary and release the covenants;

it is also possible to secure overage by disposing of the property via a long lease, coupled with a put-and-call option in relation to the reversion (ie the property disposal could be effected by means of a long lease at a low rent, with overage entitlement to be secured by a put-and-call option for the sale of the reversion by the seller to the buyer, at a price equal to overage payment due).

In practical terms, a restriction at the LR is nearly always the preferred option. See commentary in [2010] 247 PLJ 2.