Will a purchaser's lien bind a successor in title of the seller? Can the lien be protected by a unilateral notice?

A purchaser's equitable lien is a form of security that arises when a contract for sale is made. It protects part payments made by the buyer, such as a deposit.

In Williams v Alter Domus Trustees (UK) Ltd Mr Justice Miles set out the following principles applicable to equitable liens:

‘i) The purchaser's lien arises in equity to give the purchaser protection for any part-payments made under a contract to acquire an estate in land.

ii) The lien is in the nature of an equitable charge. It extends to part payments, interest and costs thrown away.

iii) It arises by operation of law and depends on there being an enforceable contract, but does not arise from the express terms of the contract and is not a implied term of the contract.

iv) The lien may be excluded or postponed to other security