Your testing window

Your “testing window” is the number of days you have to complete your questionnaire, take your samples and send them back to us. You should complete your questionnaire and take your sample(s) on the same day within your testing window.

How long is the testing window?

Before each testing window starts you will receive a letter or email telling you the dates of your testing window.

When you first join the survey, we will ask you to take your swab sample and complete your questionnaire once every week, for four weeks in a row. This means these first four testing windows will be seven days long. You may also be invited to take a blood sample with your first swab sample.

Then, we will ask you to take your sample(s) and complete your questionnaire once every month from your first testing window until the survey ends. These monthly testing windows will be 14 days long.

What do I need to do in my testing window?

Your swab kit will arrive in the post, as well as a blood kit if you are taking part in blood testing. You will need to take your samples, return them, and complete the questionnaire on the same day within the testing window.

You will need to return your samples to a priority postbox as shown on the Royal Mail Website, or in some cases you can use a courier. You can do your questionnaire online or on the telephone.

Every testing window, we will ask you to complete the steps below in the following order where possible:

• first, take your swab sample, and in some cases your blood sample

• next, complete and submit your questionnaire. be sure to click the “are you sure you want to submit” popup when it appears

• finally, send your samples back to us

Remember – these steps should be completed in order, on the same day, and within the dates shown on your email or letter. You can do them on a different day to anyone else in your home who is in the survey, as long as it is within your testing window.

If you are completing weekly testing windows, having about a week between the days you take your samples means we can better capture any changes in your test results. For example, if your testing window ends on Sunday, and you completed your survey and posted your samples on Saturday, we would encourage you to complete your next survey and samples later in the upcoming week, rather than on Monday.

If you need any support with this process, please contact us by phone or email. To reach us by phone, call 0800 085 6807, or email any queries to COVID-19@ons.gov.uk. Our contact details can also be found in the email or letter telling you about your testing window.

If you cannot use a computer to complete your questionnaire, you can complete it over the phone. Details of how to do so are in your email or letter we send to you.

Priority postboxes have extra or later collections than regular postboxes, which is why it is important to use them to return your samples.

Find your nearest priority postbox.

Not all priority postboxes have stickers on the box itself – however as long as they are listed as priority on the Royal Mail website, they are a priority postbox. Be sure to check the link above if you are uncertain.

You do not need to pay for postage. All test kits are sent with pre-paid packaging.

If you cannot get to the priority postbox yourself, you can ask someone else – such as a friend or family member to post the samples for you.

If you cannot reach a priority postbox yourself and have no-one you can ask to help, a courier service is available. Instructions on how to organise this are your letter or email.

Couriers will be available Monday to Friday, and you may need to stay at home for up to four hours for the courier to collect your samples – but this could be any time on that day.

You can book a courier to collect your samples if:

• there are no Royal Mail priority post boxes where you live

• you are classed as vulnerable or clinically extremely vulnerable

• you are too unwell to leave your home

• you find it difficult to get around

• you cannot get to a Royal Mail priority post box without using public transport

We use testing windows to make sure that we sample a wide range of representative people across the UK every week and tests are evenly spread to give us the most accurate picture of current infection rates.

We aim for everyone in the survey to give a sample roughly every month after they first join. If you do not take your sample and complete your questionnaire within your testing window, you will not receive a voucher for this testing window. You can still take part in your next testing windows, if you would like to.

If you are unavailable for a testing window, for example if you are going on holiday, you can let us know. You will have four days from receiving your email or letter with your testing window dates to opt out of the upcoming window. The email or letter has instructions on how to do this.

You will not receive a test kit in the post for any testing windows you opt out of. If you are taking blood samples, you can ask not to be sent a blood kit, and only be sent a swab kit for a certain month.

Need more help? Call us on:

0800 085 6807 – English language number

0800 917 9323 – Rhif ffôn Cymraeg, Welsh language number

Our opening times are:

Monday to Thursday – 9:00am to 9:00pm

Friday – 9:00am to 8:00pm

Saturday and Sunday – 9:00am to 5:00pm

If you have any further questions on the COVID-19 Infection Survey (CIS), email COVID-19@ons.gov.uk.