• Two adult siblings smiling together, representing sibling DNA testing
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Sibling DNA Test - Pay Lab Fee Later

Sibling DNA Test - Pay Lab Fee Later

£4.99
£4.99
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Low-cost sibling DNA sample collection kit (£4.99). Free UK standard postage included. No lab fee payable today - the laboratory analysis fee is paid later, once samples are returned.

  • Analysed by a UKAS ISO 17025–accredited UK laboratory
  • 45 genetic markers tested as standard for enhanced accuracy
  • Laboratory fee paid later, once samples are returned
  • Next working day results* once samples are received and approved for analysis

* Turnaround time:
Results are typically issued the next working day once all samples have been received and approved for analysis at our UK laboratory.

Postage information:
Free UK Royal Mail First Class postage is included with your DNA sample collection kit. Faster and guaranteed delivery options are available to upgrade at checkout.

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DNA samples being analysed in a UKAS 17025 accredited laboratory

What is a Sibling DNA test?

A Sibling DNA test is used to determine whether two individuals are biologically related as siblings by comparing their DNA profiles.

This test is commonly used when it is not possible to obtain a DNA sample from the alleged father, or when there is uncertainty about whether individuals share the same biological parents.

The Sibling DNA test can help answer questions such as:

● Are we full siblings or half siblings?

● Do we share the same biological father?

● Are we biologically related or unrelated?

Our Sibling DNA test analyses 45 genetic markers as standard, providing a significantly higher level of accuracy and reducing the likelihood of inconclusive results — which is especially important for more complex relationship testing.

Where possible, including a known biological parent (such as the mother) can further improve result clarity. There is no additional charge to include one known biological parent in the test.

This test is intended for peace-of-mind purposes and is suitable for both adults and children (parental consent required for under 16s).

The biological mother is recommended to take part where possible, as her sample helps improve clarity and reliability. However, testing can still be carried out without the mother if required. This test is intended for personal peace of mind and is suitable for adults and children of all ages (parental consent required for under-16s).

Adult sisters representing sibling DNA testing for biological relationship confirmation

Who takes part in the sibling test?

The standard Sibling DNA test involves:

● Two siblings being tested (full or half siblings)

Where possible, including a known biological parent (such as the mother) is strongly recommended, as this can significantly improve result clarity and reduce the likelihood of an inconclusive outcome.

There is no additional charge to include one known biological parent in the test.

If a biological parent is unavailable, the test can still be carried out using samples from the siblings alone. However, due to the more complex nature of sibling testing, this may slightly increase the chance of an inconclusive result.

Testing more than one child

Additional siblings can be included within the same test if required.

The correct number of mouth swabs will be provided based on the option selected at checkout.

Consent for children

Where a child is under 16 years of age, consent must be provided by a person with parental responsibility.

Clear instructions and consent forms are included with the test kit.

How Our Home DNA Test Kit Works

  • Illustration showing how to complete the consent paperwork included in a home paternity DNA test kit.

    Complete Your Forms

    Fill in the consent form and paperwork clearly. Make sure all signatures are included before returning your kit.

  • Illustration of the cheek-swab collection process used in home paternity DNA testing kits.

    Collect Your DNA Samples

    Use the cheek swabs provided, rub firmly on each cheek, air-dry for 15 seconds, and seal them in the correct envelopes.

  • Illustration showing how to package and post your completed home paternity DNA test kit samples.

    Post Your Samples

    Return your labelled envelopes, completed forms, and payment (if using pay-later) using the supplied return packaging.

Sibling DNA Testing – Frequently Asked Questions

1. How accurate is the Sibling DNA test?

Our Sibling DNA test analyses 45 genetic markers as standard, providing a very high level of accuracy when determining whether two individuals are full siblings, half siblings, or unrelated. Testing additional genetic markers significantly reduces the likelihood of an inconclusive result compared to lower-marker tests.

2. How long do Sibling DNA test results take?

Results are typically issued the next working day once all DNA samples have been received and approved for analysis at our UKAS ISO 17025-accredited laboratory.

4. Can I pay later or split the cost of the sibling test?

Yes. With our pay-later option, you pay a low-cost sibling DNA sample collection kit (£4.99) when ordering, with free UK postage included.

The laboratory analysis fee is paid later, once your samples are returned to our UK laboratory.

Where available, you may also choose to split the laboratory fee, paying part when samples are returned and the balance when results are ready. All available options are shown clearly before you place your order.

3. Who can take part in a Sibling DNA test?

A standard Sibling DNA test involves DNA samples from two siblings.

Where available, including a known biological parent (such as the mother or father) is strongly recommended, as this improves result clarity and reduces the chance of an inconclusive outcome. There is no additional charge to include one known biological parent.

5. Can children take part in a Sibling DNA test?

Yes. Children of all ages can take part. Where a participant is under 16 years of age, consent must be provided by a person with parental responsibility. Clear consent forms and instructions are included with the test kit.

6. What if the biological father is unavailable or unknown?

The Sibling DNA test is commonly used when the alleged father is unavailable for testing. In these cases, the test compares the DNA profiles of the siblings directly to assess the likelihood of a biological relationship.

7. Will anyone else know I’ve taken a Sibling DNA test?

No. All testing is carried out confidentially and discreetly. Your test kit is delivered in plain packaging, and results are shared securely. We do not notify any third parties.

8. Can this Sibling DNA test be used for legal or court purposes?

No. This test is provided for peace of mind purposes only.

If you require a legally admissible DNA test for court, immigration, or official use, this must be arranged separately with supervised sample collection. Call 0800 988 7107 to speak to one of our friendly team for more details.

9. Can a sibling DNA test result be inconclusive?

Sibling DNA testing is more complex than direct parentage testing, as it compares shared genetic markers between individuals. While most tests provide a clear outcome, there is a higher chance of an inconclusive result compared to paternity or maternity testing. If a result is inconclusive, we will explain what this means and discuss the available options to help achieve a more informative result.