A will is revocable even when it is expressed to be irrevocable and even if the testator covenants not to revoke it. In to circumstances will equity grant an injunction to restrain the testator from revoking his or her will. Statutory provisions that empower courts to vary wills to provide for dependents' relief in appropriate cases do not alter the revocable essence of a will. When a will is revoked in breach of covenant or contract not to revoke it, the testator or estate may be liable in damages or subject to some equitable remedy based upon unjust enrichment or quantum meruit. In the case of a contract to devise land, a court may grant specific performance in proper circumstances. In granting equitable relief, be it specific performance, declaration of trust or an award on the basis of unjust enrichment, the effect is not to reinstate a revoked will but to require the personal representatives (or the beneficiaries under a later will if the property has become vested in them) to execute such documents as may be necessary to give effect to the promise or covenant.
In certain circumstances, where the will is a mutual will, the promise not to revoke may give rise to a constructive trust in faivour of the will's beneficiaries. As the declaration of a resulting trust is an equitable remedy, not only must damages be inadequate, but there must be a clear connection between the services rendered by a plaintiff and the real property in question. Absent the constructive trust there may still be a monetary relief for a plaintiff in quatum meruit. In cases of real property, a decree of specific performance may be obtained. Even a devise to a third party during the lifetime of the testator may not preclude the court from making a decree of specific performance with regard to the land against the devisee. In all such actions, the property must be clearly ascertainable. There can be difficulties of proof because of the statutory requirements in some provinces that corroborative evidence is required in all actions against estates.
In actions for specific performance of a contract to devise land in return for services, the Statute of Frauds may pose problems because of the requirement of a note or memorandum in writing to substantiate the contract. There is no particular format for the note or memorandum, and a revoked will may satisfy the requirement of the Statute of Frauds if the will contains sufficient reference to the terms of the contract. A claimant may be able to rely on the doctrine of part performance to satisfy the requirements of the Statute of Frauds. Specific performance will be granted if the claimant can show acts of part performance unequivocally referable to the alleged contract and to the property itself.