1906年《海上
保险法》第18、19、和20条规定如下：
“S.18. Disclosure by assured
Subject to the provisions of this section, the assured must disclose to the insurer, before the contract is concluded, every material circumstance which is known to the assured, and the assured is deemed to know every circujstance which, in the ordinary course of business, ought to be known by him.If the assured fails to make such disclosure, the insurer may avoid the contract.
Every circumstance is material which would influence the judgment of a prudent insurer in fixing the premium, or determinging whether he will take the risk.”
（“第18条．被保险人的告知。
根据本条的规定，在订立合同前，被保险人必须向保险人告知其所知的一切重要情况。被保险人应视为知道在通常业务过程中他应当知晓的每一情况。若被保险人未作此种告知，保险人可以撤消合同。
影响谨慎的保险人确定保险费的决定或决定是否承保该项风险的每一情况，即属重要情况。”）
根据英国法律,如果在订立合同前,未披露谨慎的保险人将考虑何时决定有关是否承保该风险,或关于确定拟收取的保险费的每一情况,保险人或再保险人,有权撤消保险合同.检验的标准乃是谨慎的保险人,而非涉案的特定的保险人的决定.在Container Transport International Inc. & Reliance Group Inc, v. Oceanus Mutual Underwriting Association(Bermuda)Limited案中, 上诉法院的Kerr大法官说道:
“第18, 19条定义或限定的告知义务,是第17条提及的最大诚信的首要义务的一个方面.据此,实际的保险人有权要求向他披露将影响一个谨慎的保险人判断确定保险费,或决定是否承保该风险的每一事实.后者的词语……必须包括，不仅保险费率水平（level of premium）而且，保险人可能要求在承保范围词语中的任何条款，例如，保证，绝对免赔额(franchises)，除外等。‘Judgment’一词是在“意见的形成”（the formation of an opinion）意义上被使用。为证明某一未披露情况的重要性，保险人必须通过证据或从未告知情况本身的性质来满足法院可能性的平衡，(balance of probability)在这种意义上，若在争议问题中的情况已经披露的话。一个谨慎的保险人的意见或判断，本应已受影响。‘influenced’一词是指该披露对于他的意见的形成及对于有关第18条（2）款包含的问题他的决定过程有影响。”
Parket大法官和Stephenson大法官作出了相同效果的判决。Parket大法官亦指出：
“…在判定是否存在本条所指的未披露事实时，检验的标准是谨慎的保险人，而不是特定的保险人如何判断。”
有关海上保险领域以外的其他类型的保险（或再保险）中，法律是相同的，尽管事实上，被认定为重要的情况可能性质上有所不同。参见：例如，Lambert v.Co-operative Insurance Society Limited案 ，上诉法院就是这么判定的。
在被保险人违反其全面披露义务之场合，保险人或再保险人在发现充分事实后，无论灭失是否已经发生，可以选择自始撤消保险合同。除非且直至保险人作出此种选择，合同仍然有效。
第3款列举了无需告知的各种情况；这需要稍加解释。该款及第4、5款分别规定：
“(3)In the absence of inquiry the following circumstances need not be disclosed, namely;Any circumstance which diminishes the risk;Any circumstance which is known or presumed to be known to teh insurer. The insurer is presumed to know matters of common notoriety or knowledge, and matters which an insurer in the ordingary vourse of his business, as such , ought to know;Any circumstance as to which information is waived by the insurer;Any curcumstance which it is superfluous to disclose by reason of any express or implied warranty.Whether any particular circumstance, which is not disclosed, be material or nor is, in each case, a question of fact.(5)The term ‘circumstance’includes any communication made to, or information received by, the assured.”
（若保险人未询问，下列情况无需告知：
减少风险的任何情况；
保险人知道或推定知道的任何情况。保险人被推定知道众所周知的事情，及理应知晓他在通常业务过程中的事情；
有关保险人不要求告知的任何情况；
由于明示或默示保证条款,告知纯属多余的任何情况;
在每一案件中,未告知的任何特定情况是否重要,属事实问题.
“情况”一词包括发给被保险人的任何信息或其收到的消息.”
前条处理被保险人自已的告知义务.第19条是关于要求代表委托人办理保险的代理人或经纪人的义务.）
“S.19 Disclosure by agent effecting insurance
Subject to the provisions of the preceding section as to circumstances which need not be disclosde where an insurance is dffected for the assured by an agent, the agent must disclose to the insurer-Every material circumstance which is known to himself, and an agent to insure is deemed to know every circumstance which in the ordinary course of business ought to be known by, or to have been communicated to, him; and Every material circumstance which the assured is bound to disclose, unless it came to his knowledge too late to communicate it to the agent.”
（第19条.保险代理人的告知
若由代理人为被保险人投保,除按前条各款规定无需告知的各有关事项外,该代理人必须向保险人告知:他所知道的每一重要情况,保险代理人视为知晓其在通常业务中应当知晓或被保险人已通知他的每一情况;及被保险人有义务告知的每一重要情况,除非他得知该情况过迟,无法及时通知该代理人.”）
与未告知重要情况一样,根据英国法,若被保险人或其代理人在订立合同前误述(不真实或不准确的陈述,无论是否故意的还是无意的),无论该误述是口头的还是书面的,只要是有关保险人或再保险人评定风险的重要事实或情况,或被保险人根据保险单获得利益的重要情况,该误述起了诱使接受者(保险人)订立合同的某种作用,保险人或再保险人可以选择自始撤消保险合同.某一情况重要与否的评判标准仍然是按一个谨慎的保险人,而非依据向其作出误述的特定保险人的判断.
“S.20.Representations pending nigotiation of contract ;①Every material representation made by the assured or his agent to the insurer during the negotiations for the contract, and before the contract is concluded, must be true. If it be untrue the insurer may avoid the contract.②A representation is material which would influence the judgment of a prudent insurer in fixing the premium, or determining whether he will take the risk.③A representation may be either a representation as to a matter of fact, or as to a matter of expectation or belief.④A representation as to a matter of fact is true, if it be substantially correct, that is to say, if the difference between what is represented and what is actually correct would not be considered material by a prudent insurer.⑤A representation as to a matter of expectation or belief is true if it be made in good faith.⑥A representation may be withdrawn or corrected before the contract is concluded.⑦Whether a particular representation be material or not is, in each case, a question of fact.
