Known donation and co-parenting (UK law)

small child peeking over back of a sofa

Known donation and co-parenting arrangements cover a wide spectrum, including donation by relatives, donors with a hands-off role, and co-parents who share parenting.

If you are planning a known donation or co-parenting arrangement, it is important to set strong foundations.

If you are looking for legal help putting these arrangements in place, you can read more about how our solicitors can support you on our donor conception and co-parenting page

Known donor & co-parenting agreements

Putting in place a written known donor or co-parenting agreement is a good way of committing to a clear framework. There is no standard format, and it is important that any document is personal to you.

Planning and pre-conception agreements

Disputes in known donation cases very commonly stem from underlying mismatched expectations. You should not rush into trying to conceive, and make sure that you discuss the roles you each intend to have. Be as clear as you can about what you want, and be honest with each other and yourselves. It is important to talk about your roles generally, as well as day-to-day practicalities.

Pre-conception agreements are not legally binding under UK donor and co-parenting law. This means that the family court is not obliged to follow what they say if there is a dispute, and they do not override the legal position as to who is legally and financially responsible as a parent.

Co-parenting and donor agreements provide evidence of intent in disputes

Although known donor and co-parenting agreements are not strictly enforceable, they provide clear evidence of what was intended and may carry weight in court if there is a dispute (and will at least prevent argument over what was agreed, which is a common feature of disputed cases). 

By facilitating discussions, at the outset, which helps everyone to enter into an arrangement with clarity and consensus, written agreements can also have a significant impact on preventing a dispute from ever arising.

There are no fixed requirements for 'formalising' pre-conception agreements for known donation or co-parenting (they do not, for example, need to be witnessed by a solicitor). However, an agreement is likely to carry more weight if it is legally accurate and if the parties have had legal advice before it is signed.

Known donor and co-parenting law: Understanding legal parenthood and responsibility

The law dictates who the legal parents are (and who has parental responsibility), irrespective of what the adults have agreed. Under UK law a child can have no more than two legal parents. The birth mother (or person who gives birth, if they are transgender) is always the legal mother and must be registered on the birth certificate. The other legal parent is either their spouse/ civil partner (find out more about parenthood for non-birth mothers and fathers who conceive with donor sperm) or possibly the biological father (find out more about the parenthood of sperm donors and co-parents).

If the legal parents are married or in a civil partnership with each other, they must both be recorded on the birth certificate and they share parental responsibility automatically. If they are not married or in a civil partnership with each other, then they can choose whether to register the second parent on the birth certificate (both must agree if they want to do so). This is a significant decision, since it will give the other parent parental responsibility.

Altering the legal position

It may be possible to agree to take steps after the birth to alter or add to the basic legal position which applies at birth. For example, a non-birth mother can adopt her child (extinguishing the status of a known donor who is the legal father); non-legal parents can acquire parental responsibility. 

Find out more about securing parental rights for non-birth mothers and in co-parenting situations.

If those involved do not all agree, the law is much more complex. Find out more about co-parenting and known donor disputes.


Have we answered your question? Would you like advice on your personal circumstances?

Email us at or call on 020 3701 5915 and we will explain how we can help.