There is no law that you have to answer a solicitors letter. You have to answer a court summons and nothing else. I hope that helps. Please leave a positive rating so that I am credited for my time.
Thank you for your question
My name is ***** ***** I have been a solicitor for more than 30 years.
It is always better to avoid court proceedings if possible - so the answers will depend on whether the children live with you or not - and what this issue is
If you need further assistance my colleague will be more than able to assist you