When email can change the substance of a contract

Imagine placing a purchase order for consultancy services or new laptops. The supplier replies at once: “Thank you for your order. We can deliver if the price is increased by 7 per cent.” That response is not an acceptance – it is a rejection coupled with a new offer. If you then do not reply but still accept delivery, your acceptance by conduct may be interpreted as agreeing to the revised contractual terms.

A binding contract at the higher price may therefore have arisen – even though you never expressly said yes.

Contract law: clear on paper, blurred in email negotiations

Under the Contracts Act (1915:218), an offer must be accepted without changes. If anything changes – price, payment terms or delivery time – it is no longer an acceptance. Instead, a fresh contractual proposal has been made and requires a new response from the counterparty.

A short email can therefore reshape the contract formation – without you noticing. In legal terms, the supplier made a new offer at a higher price. By taking delivery without protest, you can be deemed to have accepted that counterproposal through acceptance by conduct (and sometimes acceptance by performance). Seemingly routine order confirmation exchanges in email negotiations can harden into binding offer and acceptance.

Many companies lack clear procedures for handling counterproposals from suppliers. The result can be unfavourable contractual terms, price increases and, in the worst case, contract negotiation and enforcement disputes.

Our recommendations – avoiding legal pitfalls in email negotiations

To keep control over your contractual terms, you should:

• Always reply to emails that introduce changed terms, rather than relying on silent acceptance.
• Formally accept or reject each counterproposal in writing after appropriate contract review.
• If you accept the change, place a new purchase order or restated order confirmation that clearly sets out the new offer and the agreed price.

This is particularly important in sectors involving substantial sums or rolling deliveries. A single misstep in offer and acceptance can be costly.

Small replies, significant consequences

Contract formation does not happen only in formal documents – it also happens in brief emails, swift replies or through silence. Legally, each step can have material, unintended effects. At Morling Consulting, our commercial contract lawyer team supports businesses from first contact to finalised contract negotiation. Speak to a contract lawyer or arrange a retainer contract lawyer to reduce risk and secure your position.