邮政规则自英国法院成立以来得到进一步完善。在重新伦敦和北部银行的情况下，[ 8 ]认为，邮政接受是无效的，因为适当的邮政程序不遵守。在案件的事实中，一个党允许邮递员接受一封录取信（与其他信件捆绑在一起）当他提出把他们的党。如此肯定的概念，接受被认为是执行的那一刻起，这是张贴，[ 9 ]然而发现邮递员是禁止的，邮局的规定下，采取任何后收费。这意味着邮递员在这方面没有被授权担任邮局的代理，因为他被特别禁止处理任何他不负责递送的邮件。因此，法院认为，邮政承兑没有贴上正确的标签，因此不能说符合邮政规则的隐含条款。鉴于这一案件在一个世纪前决定，它在现代语境中提出了问题。例如，邮政规则可以延伸到私人快递服务，一个文件是由信使拿起？有人会这样想，因为一个信使作为快递服务的代理，这将是符合在伦敦和北银行[ 10 ]和Harris的情况下所列的原则，[ 11 ]有关机构的原则，涉及邮局。
The Postal rule has been further refined since its inception by the English courts. In the case of Re London and Northern Bank, it was held that a postal acceptance was not valid, as proper postal procedures were not adhered to. It emerged in the facts of the case that a party had allowed a postman to take a letter of acceptance (bundled with other letters) when he offered to post them for the party. The case affirmed the notion that an acceptance is deemed to be enforceable from the moment it is posted, however it was discovered that postmen are prohibited, under the regulations of the Post Office, from taking charge of any post. This meant that the postman was not authorised to act as an agent of the Post Office in this regard, given he was specifically prohibited from handling any post that he was not charged with delivering. Therefore, the court held that the postal acceptance was not pasted correctly, and hence could not have been said to have complied with the implied terms of the Postal rule. Given that this case was decided over a century ago, it raises questions in the modern context. For example, can the postal rule extend to private courier services, where a document is picked up by a courier? One would imagine so, given that a courier acts as an agent of the courier service, which would be consistent with the principles set out in Re London and Northern Bank and Harris’ Case, regarding agency principles involving the Post Office.