How Long Does A Paternity Test Take?

There are a number of reasons why someone might need to take a paternity test. It could be to solve a legal issue pertaining to future child support or amending a birth certificate.

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There might be a medical aspect to the inquiry. Sometimes it’s simply a matter of curiosity, but whatever the impetus, you’ll likely want the results sooner rather than later.

How Long Does A Paternity Test Take

Waiting for the lab’s response can be extremely stressful for all interested parties, especially if it concerns the future of a newborn. All of a sudden it can feel as if your life is on hold, and your future, unsure.

Unfortunately, there’s no way to completely alleviate these post-results anxieties, but learning about the time frames in which labs work can help to ease your mind and prepare yourself for the outcome.

What Does A Paternity Test Involve, And How Long Does It Take To Complete?

There are actually a few different types of paternity test, so let’s take a look at each one individually, discuss what they entail, and when you can expect to see the results.

Postnatal Paternity Tests

A postnatal paternity test is the most common of all, and it’s a very simple procedure. There are no needles involved, nobody takes any blood from anyone, all that’s required is a saliva swab from the inside of the possible father’s cheek, and the same from the child.

It takes all of a few seconds. In some instances, a DNA sample will also be taken from the mother’s cheek too. The samples will then be transferred to a lab where the paternity test will be carried out.

When Will You See The Results?

Much like any workplace, labs can become quite busy, so it’s hard to say exactly how long a waiting period will be, but thankfully, postnatal tests tend to have a faster turnaround than some others.

Generally speaking, a well-staffed laboratory with all the relevant accreditations should be able to tell you if the test taker is the biological father of a child within 3 – 4 business days. Others will give you a timeframe of 5 – 8 working days.

Labs with fewer facilities, staff, or more stringent test protocols may work within a much larger time frame — we’re talking 3 – 12 weeks.

There are also a number of other factors that can affect the length of your waiting period, including:

  • Distance

Sometimes the DNA samples have to be ferried around before the test can be conducted, thereby prolonging your wait.

This could be because the testing lab is separate from the location where the samples were taken, or it could be that the possible father lives quite far away from the lab.

In some scenarios, a lab carries out the paternity test efficiently but has to then send the results to a certain authority before you can access them.

For example, the lab might be bound by law to send the results to Citizenship and Immigration Services, after which, you’ll have to request the results from the Passport Office.

As it takes time for the authority to receive the results, process them, then contact you, the waiting period can be drawn out by days, sometimes even weeks.

  • Method of Return

A lab may ask you how you wish to receive the results. If you prefer to receive them as a letter, you can expect to wait a little longer, but an email can be sent instantaneously. For this reason, many labs use an email service as standard.

  • Expedited Options

You’ll also find that certain laboratories offer expedited testing options for an extra fee. These fast-tracked testing services can cost a pretty penny, but they’ll usually get the results back to you on the same day the lab receives the samples or the next working day at the latest.

  • Student Staff

Some labs employ students to help out with testing procedures. Technically speaking, these employees are classed as non-scientific members of staff, and their involvement can slow down both the testing process and the completion of the analysis report.

  • Booking 

One of the oft-forgotten hold-ups in the paternity test process is that you have to wait for a test to arrive. Dispatch times and postal services can differ from company to company.

Father holding Newborn Baby

Prenatal Paternity Tests

Non-Invasive Prenatal Paternity Test (NIPT)

NIPTs involve a cheek swab from the possible father and a sample of a mother’s blood during the first trimester of their pregnancy. The fetal DNA within the mother’s blood can then be compared to the DNA collected from the potential father’s DNA swab.

When Will You See the Results?

A well-run lab with high-quality facilities and well-trained staff should be able to get the results of a non-invasive prenatal paternity test back to you in 3 – 10 working days. That said, a lot of the same variables that affect the duration of a postnatal paternity test also apply to NIPTs.

Chorionic Villus Sampling (CVS)

CVS involves taking a small sample of placenta via the mother’s cervix or abdomen and comparing the DNA with the potential father’s cheek swab.

When Will You See the Results?

CVS testing typically takes a little longer than NIPT or postnatal paternity tests. The average waiting period is usually around 2 weeks, but, again, this figure can differ significantly from lab to lab.


In this procedure, a needle is pushed through the mother’s abdomen or cervix in order to draw out a tiny sample of amniotic fluid. The DNA within the fluid will then be compared to the DNA of a cheek swab.

When Will You See the Results?

Paternity testing via amniocentesis is quite a complicated process, so you should expect to wait several weeks for the results to make it back to you.

Summing Up

How long you’ll be waiting for the results of a paternity test depends on how the lab responsible for doing the test is run and the way in which the DNA samples are gathered.

Some labs pride themselves on a speedy turnaround of between 3 and 4 business days, but others can take as long as 12 weeks to post the results.

Any lab specialist worth their salt will inform you of their usual waiting periods, but if they haven’t, or if you have forgotten, don’t hesitate to ask.

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