Joint Mutual Will becomes irrevocable on the death of one of the testators:

The Bench decision of this court in KUPPUSWAMI v. PERUMAL (AIR 1964 Madras 291) wherein Ramamurti, J. tracing the law from Roman Dutch Law relating to joint and mutual Wills and after referring to earlier decisions in India as well as in England and also after referring to Corpus Juris Secundum and after referring to the decision of this Court in Meenakshi ammal v. Viswanatha Aiyar (ILR 33 Madras 406) and the decision of Allahabad High Court in Bhavani Prasad v. Surendra Bala (AIR 1960 All 126) held as under:-

"We confess that the matter is not free from difficulty. But after a careful consideration of all the aspects of the matter, we are inclined to take the view that a joint mutual Will becomes irrevocable on the death of one of the testators if the survivor had received benefits under the mutual Will, and that there need not be a specific contract prohibiting revocation when the arrangement takes the form of not two simultaneous mutual Wills but one single document. In fact in some of the cases referred to above this aspect that if the two testators had executed one single document as one single mutual Will the position may be different is actually adverted to. In our opinion, if one single document is executed by both the brothers using the expressions 'our property, 'our present wishes' 'our Will' and such similar expressions, it is strong cogent evidence of the intention that there is no power to revoke except by mutual consent".

Learned Judge after considering relevant case laws laid down the tests as to when mutual Will is irrevocable in para-24 of the judgment which runs as under:-

" From the above discussion of the relevant cases, it will be clear that under the English law in order to render mutual Wills irrevocable, both the conditions must be concurrently satisfied; (a) the surviving testator must have received benefits from the deceased under the mutual Will and (b) the mutual Wills should have been executed in pursuance of an agreement that the testators shall not revoke the mutual Wills. Such an agreement not to revoke the Wills may either appear from the Wills themselves or may be proved outside the Wills. 

Vide 39 Halsbury 3rd Edn. by Lord Simonds page 553, para 1289 and 1914 P.192."