If, for whatever reason, the previous agreement is not expressly included, this earlier agreement may, in certain circumstances, give rise to a legally binding obligation, even if the contract contains a full contractual clause. This is due to the Estoppel doctrine by convention, which was recently discussed under the comprehensive contractual clauses contained in Mears Ltd/Shoreline Housing Partnership Ltd3. In this article, we give a brief overview of the interaction between entire contractual clauses and unspoken clauses in English law, in reference to the recent Court of Appeal case of J N Hipwell – Son/Szurek (Hipwell), 1 in which a complainant attempted to convince the Court of Justice that an implied commercial agreement clause should be with a full clause in the contract. Finally, we draw attention to some practical aspects of the law in these areas that may be important to energy and natural resources companies. A full clause of the contract is intended to clarify that the agreement between the parties is exclusively what appears in the written contract and prevents the contracting parties from subsequently making claims which, during the negotiation of the contract and prior to the signing of the written contract, constitute additional terms of the contract or some form of ancillary agreement. In other words, the parties include a full contractual clause in the contract to prevent these pre-contract and guarantee statements from complying with the contract. In the energy and raw materials sectors, contracting parties will often encounter «full agreement clauses» to limit the scope of an agreement to the conditions expressly mentioned in the treaty. If there are already contracts that must remain in force at the time of the new agreement, their use can be very dangerous. In addition, contractual clauses themselves are increasingly a source of litigation in the energy and raw materials sectors, where financing and supply agreements are generally long-term and where, as such, the effects of litigation on the validity of a comprehensive agreement clause can be serious.

However, the exclusion of a tacit clause depends not only on the drafting of the entire contractual clause, but also on the nature of the tacit clause and, in particular, whether it is considered «intrinsic» or «extrinsic» of the written agreement. In the case of complex or higher-value transactions, an unrestricted comprehensive contractual clause may be unjustified because it can cause more problems to one or both parties than it resolves: it may terminate all previous contracts between the parties. 4. Previous agreements and agreement by agreement – Finally, when entering into a contract, the parties should consider whether the agreements reached before the treaty are concluded and which should be included in such a contract. In this case, this should be done by explicit reference to this agreement and its inclusion in the new treaty. If this has been done correctly, a whole contractual clause will not work to exclude it. Although this was the decision of a Masters to summarise the reasons for judgment, it draws attention to the dangers of a rigid approach to the interpretation of the standard clauses of the boiler platform. As with any other clause, they are always interpreted as part of the overall contract. However, in the design phase, it is risky to rely on the Tribunal adopting a more comprehensive view of the interpretation of the standard basic rules (such as the fact that the decision was overturned in November 2018 in the context of an appeal).