Assume that my website offers a service requiring registration and payment - i.e. the service is NOT available by just typing the website address in the browser. Considering this service, I'm wondering if it's fine to update my website T&Cs with:

  • immediate effect for new users;
  • 30 day delay for existing users (as stipulated in T&Cs themselves).

This would obviously create a period of time when some users are bound by version X and some users are bound by version X+1.

I wonder if there are some (consumer?) laws that specifically prohibit such a duality.

Some reasons why this may be desirable:

  • price increase for new users without delay;
  • giving access to new features for new users without delay.

I also realize there are significant administrative disadvantages to managing this dual state while it lasts.


A (very helpful) answer raised doubt about changing the T&Cs for existing users after the notice period. I should have mentioned: existing users have the option to refuse the change, which would terminate the contract, again, as stipulated in the T&Cs themselves. As far as I'm aware this approach (if existing users refuse, end of contract) is universal for online services. Though this is not the focus of my question: the focus is the legality of the temporary dual state, where some users are on T&Cs version X, and some are on T&Cs version X+1.


2 Answers 2


Can a website terms and conditions change bind: (1) new users immediately, (2) existing users after a contractual notice period?

It can bind new users immediately. The matter is more uncertain and/or complex in regard to existing users because, inter alia, a party's unilateral and belated imposition of new terms contravenes a tenet of contract law that the parties enter the terms of an agreement [willfully and] knowingly.

With respect to existing users, what you outline is an amendment of contract. All parties to a contract have to agree to an amendment. Otherwise the amendment is not binding. This means that you would have to maintain the old version of your service for as long as a contract with an existing user is in place. If existing users reject the amendment and decline to rescind/void the contract or terminate it early, there is little or nothing you can do (i.e., other than continue performing the contract) lest you opt for [an actionable] breach of contract.

Contract law typically leaves room for exceptions on the ground that it is reasonable in the circumstances to do so. Your description is too generic for us to assess whether that would be the case here, though.

  • Thank you very much! I'm sorry I didn't explain at first that existing users can refuse the change, terminating the contract. AFAIK, this is how it's (almost?) always done for existing user base. Edited the question to make it clear. Commented Sep 25, 2021 at 13:46
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    @JanŻankowski "the focus is the legality of the temporary dual state". The dual state is perfectly legal, and it does not matter whether it is temporary or permanent. What matters is that each user was made aware of the terms at the formation of his contract, which seemingly happens in your scenario. "existing users can refuse the change, terminating the contract." The lawfulness of that depends on whether the original terms (i.e., from when the existing user entered the contract) provide for early termination in the event that the user rejects subsequent changes in the T&Cs. Commented Sep 25, 2021 at 18:00

I can accept your terms or conditions or I can not accept them. You may have a license saying “You only have permission to read this website if you accept the terms and conditions”. That gives me three choices: Not read it, read it without a license, or agree to your T&Cs and read with a license.

Worst case you could take me to court, and it would be up to me whether I admit that I read your website without the license, or whether I admit that I agreed to your T&Cs. I will obviously do what is least bad for me.

  • Thank you for contributing, but I don't see how this is meant to answer my question. I'm not asking about what to do if someone doesn't accept my T&Cs. Plus in the case I have in mind it's impossible to use the service without accepting T&Cs. I'm asking whether it is legal that some users have to agree to a new T&Cs version while others are still bound to the old version. I will happily remove the downvote if you change your answer along these lines. Thanks! Commented Sep 25, 2021 at 14:04

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