The short answer to this question is usually ‘yes’
When a divorce or separation is difficult children’s holidays abroad with one parent can be contentious although one would always hope a parent would not want to deprive their children of a holiday or travel experience. It is always reasonable to expect the other parent to provide details of a planned holiday including flight/travel details, address/type of accommodation and who else will be travelling with your children.
Both parents usually have parental responsibility (unless they are not married and the father is not on the birth certificate) so you each need the agreement of the other to take the children abroad. It’s wise to take with you a signed letter from the other parent giving their consent. There is a Home Office template for such a letter here:  although you may not need all the detail, just amend it to suit your own needs.
Such a letter is not a legal requirement in this country but border controls around the world are getting stricter due to the increasing numbers of children being abducted. So if you are stopped it will be much easier if you have such a letter, and you might also need it if for instance your child required medical attention abroad.
You may also need documents such as your birth, marriage or divorce certificate to prove you are related to the children if you have a different surname. You also need to check on the entry requirements of the destination you are travelling to as some, such as the US and South Africa, require more formal proof that your children have the right to enter the country without the other parent. And some countries have different age limits for when a child is considered an adult. You should also check with the airline you are travelling with in case they have different requirements.
If grandparents are taking children abroad, they will need a letter signed by both parents.
If you are unable to reach agreement about a holiday abroad mediation is the best way to resolve it. If you still can’t agree, you will need to ask the mediator to sign a C100 form so that you can apply to the court for an order allowing you to take your children on holiday.
If you have a court order for the children to live with you (ie a residence order or child arrangements order) you are entitled to take your children abroad for up to 28 days without your ex’s permission – but do make sure you take the court order with you. Your ex would still need your permission in the usual way.
Occasionally parents want to move abroad after a divorce, particularly if their family live in another country and they need their support as a single parent. If you want to do this, you need either the written agreement of your ex, or a court order allowing you to remove your children from the jurisdiction (ie England and Wales). The court would need to be satisfied that the move is in the best interests of your children.
Please don’t be tempted to take your children abroad without agreement or a court order: child abduction is a serious criminal offence for which parents are given lengthy prison sentences these days.
If you need any more information about any of this please drop me a line: diana@dealingwithdivorce.co.uk or give me a ring on 01932 843434.