Hi, thank you for your question. Just a bit more information required to fully assist you:
-Are you all in England or Wales?
-How old is your son?
-What are the arrangements for him?
Thank you for confirming. Firstly as the mother you have parental responsibility and he cannot remove your son from the country without your permission. If you think that he will be leaving with him and if he has travel documents/passport for him then you can urgently apply to court for a prohibited steps order using form C100 and a £215 court fee to your local family court to prevent the travel.
In relation to the change of name as you are married you must obtain agreement from your husband to change the name and if no agreement can be reached, you again will need to apply to court but this time for a specific issue order, again using form C100 and a £215 court fee.
I hope this assists you. If you found this information helpful please provide a positive rating using the stars at the top of this page. I will not be credited for your question without a positive rating. Thank you.