There are multiple reasons for wanting a paternity test. Read our expert guide to doing it right and getting the right results.

What is a paternity test?

Paternity testing is used to establish the relationship between a child and one or more alleged fathers. A DNA sample is collected from the child and each potential father (usually via a cheek swab). In some instances a third sample is taken from the mother, although this isn't necessary.

There are two possible outcomes from a paternity test – it will either confirm that the two individuals are -NOT- related, or it will confirm that they -ARE- related with over 99.99% accuracy. The test essentially gives a yes/no answer.

How does paternity testing work?

There are a number of ways to collect a person’s DNA, but the simplest method is a buccal swab (cheek swab). It’s safe, fast, non-invasive and painless. In a standard relationship test, a swab is taken from two individuals. The samples are then sent off to a testing lab for analysis, and the results are can be emailed or posted back to the instructing party – typically within a few days.

Some DNA testing companies can also extract DNA from a person’s toothbrush. This is useful if a sample is needed from older children, as it can be done discreetly and avoids having to answer difficult questions. Be aware though that anyone over 18 must provide their written consent to be tested. With children, the person with parental responsibility must give consent on the child’s behalf.

What are the different types of test?

There are two main types of paternity test. There's a peace of mind test that can be carried out in the comfort of your own home. The results are simply for your own peace of mind, and cannot be used to settle legal matters.

Then there's a legal test which is carried out by a doctor or a trained sample collector. The samples are transported back to the testing lab under a controlled chain of custody. A legal test can be used to settle legal disputes and immigration matters.

Both legal and peace of mind tests are accurate, but only a legal test can be used for official matters.

Can you have do paternity test during pregnancy?

Yes. In the past, a prenatal paternity test was a risky and invasive procedure which most doctors refused to do unless there was a serious medical reason. Nowadays however, scientists have developed a safer method that simply involves taking a blood sample from the mother. The father provides a cheek swab and the two DNA samples are compared in the laboratory.

How much does a DNA test cost?

The cost of a DNA test depends on a number of factors – such as the type of test, how many people are involved and how quickly you want the results. A basic peace of mind test with one child and one father can cost as little as £100, whereas a prenatal DNA test involving multiple people could cost in excess of £1,000.

How do I find a good testing company?

If you look around online you'll find several DNA companies offering their services. Whichever you choose, make sure they are an accredited lab – look out for ISO certifications and check to see if they are approved by the Ministry of Justice.