The answer to this question depends partly on the status of the children in question. If they can prove that they were dependent on you or are in financial need, and that you have not properly provided for them in your will, they may be able to persuade a court to make provision for them from your estate.

If you intend to do anything that might appear to be unfair, you should provide reasons. For example, you might explain that you are excluding your older son because he had his share when he was setting up in business.