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. 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 summary, the parties should ensure that they are informed in advance of what was included prior to its execution and that it has been excluded from the contract. As we have seen, it is often necessary to include additional clauses in the contract in order to exclude unspoken clauses or pre-contract assurances or to include certain pre-contract agreements. Otherwise, a simple misunderstanding could lead to costly litigation. „This contract contains final and comprehensive agreement and agreement between the parties and is the full and exclusive declaration of its terms. This contract replaces all previous written or written agreements in this context. Questions about the effectiveness of whole contractual clauses are increasingly being raised in litigation, particularly in disputes related to long-term contracts such as joint ventures, long-term supply contracts, long-term financing agreements or amendments and/or extensions of such agreements or agreements in which the parties have had a long period of activity. Questions often arise when disagreements over the importance and effect of such contracts or agreements occur and when a party attempts to look outside the terms of the contract to support a claim, defence or argument. The final contract contained a full contractual clause.
Shoreline argued that this clause had prevented Mears from availing itself of the pre-contract agreement. However, Akenhead J noted that „the full agreement clause“ does not exclude or limit confidence in an established and effective Estoppel, either explicitly or by interpretation. It was found that prior to the start of the contract, the parties shared an assumption and based on this assumption over a long period of time, so it would be unfair to allow Shoreline to apply the terms of the contract in order to avoid the performance of their obligations under the pre-contract agreement. 3. Correction – A third limitation of a full clause of the contract is that it cannot be invoked to prevent the correction of a unilateral or common error in circumstances where a contract is not a real representation of what has actually been agreed by the parties. First, such a clause does not prevent the parties from relying on „extrinsic“ statements or documents in the contract – that is, documents that can be used to inform the importance of the contract (although such extrinsic documents cannot be used to establish a separate contractual agreement between the parties).