Paternity and DNA testing in the family court

Who is a child's legal father matters for parental responsibility, maintenance,

inheritance and the child's identity. When it is disputed, DNA testing can settle it —

but in family proceedings you normally need the court's permission, and unauthorised

tests have real consequences.

REVIEWED BY: Sean McNamara on 2026-08-31

Why paternity matters

Parental responsibility (PR): a married father automatically has PR; an unmarried father has it if named on the birth certificate (after 1 December 2003) or via agreement/court order. If paternity is wrong, PR can be affected
Child maintenance: the CMS assesses the legal/actual parent; disputed paternity can suspend or redirect assessments
Financial claims: Schedule 1 Children Act 1989 claims and step-parent arrangements turn on parentage
Birth certificates: the court can order the registrar to correct or add an entry
The child's welfare and identity: courts treat knowing one's biological origins as part of a child's welfare, especially as they grow older

Legal parenthood is not always biological

Legal fatherhood can arise from marriage, birth registration, agreements, or adoption — not only DNA. A man can be the legal father without being the biological father, and vice versa (in rare cases, e.g. unregistered biological fathers). That is why the court, not a test alone, defines the outcome.

Getting a test — two routes

1. Court-directed testing

In proceedings, a party can ask the court for a direction for scientific tests to determine paternity under section 20 of the Family Law Reform Act 1969. The court can direct that samples be taken from a child and any relevant adult. Practice:

Apply by short application (form C2 in children cases) with your reasons
The court decides whether the test is in the child's interests — it nearly always is where parentage is genuinely disputed
Testing is done by an accredited laboratory; the court will name or approve one
The cost is usually ordered against the applicant or shared — expect roughly £400–£600 for a standard mother/child/alleged-father test

2. Private ("peace of mind") testing

You can buy a home DNA test privately, without the court. But be careful:

A private test is not admissible evidence in court proceedings as a conclusive scientific report in the same way; you may still need a court-directed test
Taking a sample from a child without appropriate consent (from everyone with parental responsibility) is unlawful — breaches of DNA and data rules can lead to criminal and civil consequences
Never test covertly "to find out first" — courts take a poor view and it can damage your case

Consent to sampling

Section 22 of the Family Law Reform Act 1969 sets the consent rules. A child's consent depends on age and understanding — a child old enough to understand can refuse. Younger children: consent comes from a person with parental responsibility. If someone with PR refuses sampling, the court weighs the child's interests; it cannot force a sample where refusal is lawful, but refusal itself is evidence the court can weigh.

What happens with the result

An accredited report goes to the court and the parties
If paternity is established: the court can make a declaration of parentage (s.55A Family Law Act 1986) and order birth certificate corrections; PR can follow (for unmarried fathers, via order or agreement, or by the declaration being registered — seek advice on the route)
If paternity is excluded: the presumed father's obligations (maintenance) and status adjust; the child's care arrangements are then decided on welfare, not parentage alone — an excluded "father" who has cared for the child may still have standing under s.10(5) CA 1989 to apply for orders

Practical tips

1. Ask for the direction early — testing delays otherwise cause timetabling problems 2. Never instruct a lab yourself mid-proceedings without permission (see our Part 25 experts guide) 3. Keep the tone child-centred: judges dislike paternity disputes used as leverage 4. If a child is old enough, consider their views — courts increasingly hear the child's voice on identity questions

Official links

Family Law Reform Act 1969, ss.20–23: https://www.legislation.gov.uk/ukpga/1969/46
Family Law Act 1986 (declarations of parentage), s.55A: https://www.legislation.gov.uk/ukpga/1986/55
C2 form: https://www.gov.uk/government/collections/family-court-forms
Child Maintenance Service: https://www.gov.uk/child-maintenance
Registering/correcting births: https://www.gov.uk/register-birth

This page is general information, not legal advice. YourFamilyCase.co.uk is an independent information directory and is not affiliated with HMCTS or gov.uk.

Content verified against the official HMCTS court directory, gov.uk forms and fees pages, and the professional body registers (SRA, FMC, Bar Council). Last reviewed September 2026.