Summarises the case of William Page v BNP Paribas, 4 September 2008. Words may not mean what they say if such an interpretation would go against business common sense. A claimant tenant sought to exercise its option to extend a lease on prime retail premises in London's West End by 10 years. The landlord argued that the tenant had lost this right by breaching the terms of the lease due to an invalid notice. The tenant paid by a company related to the tenant on its behalf, which the landlord argued meant that a third party had been allowed into occupation. Judgement was for the claimant: the lease terms had not been breached because the landlord was fully aware of the arrangement when the letting was agreed and the other party was simply acting as an agent for the claimant. Agreements have to be interpreted strictly, but not to the exclusion of common sense or commercial purpose.