The number of Covid cases has risen by 14 per cent in a week, according to the Office for National Statistics (ONS), in a sign that the autumn wave of infection is underway.

More than 1.1 million people in the UK tested positive for the virus in the week ending September 20, up from 927,000 in the previous week.

While infections are continuing to rise in England and Wales, the trend remains uncertain in Scotland and Northern Ireland, the ONS said.

In the capital, an estimated 1.79 per cent of the population was thought to be infected in the week ending September 17 - the highest proportion in a month.

But what are lateral-flow tests and where are they available?

Here’s everything you need to know.

How can I get a lateral-flow test now?

People who are not eligible for lateral-flow tests can buy them at pharmacies and certain retailers. It’s possible to buy LFTs both online and in person.

What do I do after taking a lateral-flow test?

If you were eligible for a free lateral-flow test through the government, you can report your result online.

However, if you paid for your test, you cannot report your result through the government website.

If you test positive for Covid, the NHS advises that you “should try to stay at home and avoid contact with other people for five days after the day you took the test”.

How much do lateral-flow tests cost?

Lateral-flow tests are much cheaper than PCRs.

High-street options include Boots with a single test for £2.50, £12 for a pack of five, or £17 for four, with an option to send results to the UK Health Security Agency (UKHSA).

Elsewhere, Superdrug is selling Healgen for just £1.99. Both stores offer Flowflex multipacks for just under £10.

Government-listed provider Randox offers packs of three tests for £6 and packs of 10 tests for £17.

When did free Covid tests end?

Free lateral-flow tests were provided to the public until Friday, April 1.

Ordering tests from the government website included answering questions on whether you had symptoms.

If answered no, a message stated that tests are “most needed” for those at higher risk.

When could free Covid tests come back for the wider population?

Free testing could be reinstated if a dangerous new variant arises, so the Government is storing lateral-flow tests as a pre-emptive measure.

Lateral-flow tests remained free in Wales until July 31, while free lateral-flow tests are no longer available to most people in Northern Ireland.

The ONS suggests that, as of August 8, about one in 50 people in Northern Ireland have had Covid.

Who can still get free lateral-flow Covid tests?

Currently, most people in England can’t get a lateral-flow test for free, although certain groups are still eligible.

The groups of people who may be able to get LFTs for free include the following:

• People who are eligible for Covid treatment

• People in care homes, refuges, and prisons

• People who are being admitted to hospital

• People who work in the NHS or adult social care

You are eligible for free tests if you work in the NHS or adult social care and you’re:

• NHS patient-facing staff

• staff who deliver NHS services through an independent healthcare provider, and have direct contact with NHS patients

• a social worker

• a personal assistant

• a Shared Lives carer

• a Care Quality Commission (CQC) inspector

Additionally, people can also get a free LFT if their GP or a health professional has asked them to get tested.

There are currently no plans to reintroduce free Covid testing for the general public by the Government, despite cases rising and being close to record highs again.