The change is part of the government's "Living with Covid-19" plan.
Free lateral flow tests (LFTs) will no longer be available in England from 1 April, except to the over-75s and people over the age of 12 who have weakened immune systems.
Anyone else will have to buy a test from pharmacists or other retailers. The government has indicated it expects individual tests will cost a few pounds.
The number of tests distributed each day in England has already been capped "to manage demand".
People without symptoms can now only order one pack of seven LFTs every three days - previously they could order one per day.
Free PCR tests will no longer be available in England from April either, except for a small number of at-risk groups, details of which will be announced in March.
There will also be free testing for social care workers with Covid symptoms.
Meanwhile, Scotland is due to set out its "Living with Covid" plans later on Tuesday.
Anyone without Covid symptoms can order LFTs online using their NHS login.
You can also collect LFTs from pharmacies, vaccination hubs and test centres, but you may need to register online to get a "collection code" first.
You should report all LFT results online or by calling 119.
People with symptoms can order a PCR test kit to be sent to their home or book an appointment at a walk-in or drive-through test site.
* England: From 24 February, if you test positive for Covid, you are advised - but not legally required - to self-isolate for at least five days
* Northern Ireland: You are "strongly advised" to self-isolate for 10 days after testing positive, with an opportunity to leave from day six if you test negative on two consecutive days
* Scotland and Wales: If you test positive, you are legally required to report your result online or by calling 119, and self-isolate for at least seven days, and then until you have two negative LFT results, 24 hours apart
If you are fully vaccinated (two doses - three in Scotland), you don't have to self-isolate, but should take daily LFTs for seven days (or for 10 days after your last contact, if this is earlier).
If any of the LFTs are positive, you must self-isolate from the date of the test. You do not need to confirm the result with a PCR test.
Close contacts of positive cases who are not fully vaccinated still have to self-isolate for the full 10 days. In Scotland, they are advised to take one PCR test and continue isolating even if the result is negative.
In Wales, unvaccinated contacts are advised to take LFTs on days two and eight, even if they have no symptoms.
Anyone who develops Covid symptoms during self-isolation should take a PCR test.
From 24 February, routine contact tracing in England will also end. People who have been in contact with a positive case will no longer be required to self-isolate or be encouraged to take daily tests, even if they have not been vaccinated.
There will instead be guidance on how they can reduce risks to themselves and others.
Staff and students in most education and childcare settings in England are no longer encouraged to test twice-weekly. Arrangements for NHS staff will be confirmed in March.
In the rest of the UK, NHS and education staff are still asked to test twice a week. Secondary pupils should test twice a week during term time (three times a week in Wales).
People can also provide a recent negative LFT or PCR result instead of proof of vaccination to enter venues across the UK that are still covered by Covid passport schemes.
From 1 April, the government will no longer recommend that venues in England use the NHS Covid pass.
You may need to still test before or after travelling abroad. You must buy private tests for this - you cannot use free NHS tests.
LFTs and PCR (polymerase chain reaction) tests do different things:
* LFTs pick up the most infectious people by detecting material from the surface proteins of the virus
* PCRs detect genetic material of the virus which can be present in the body for several weeks after somebody is actually capable of passing it on
Both tests involve swabbing your nose and/or throat. LFTs can be done at home, and show results in 20-30 minutes.
PCR test swabs must be sent to a lab for analysis, with results provided in 24-48 hours, although it can take longer to confirm a particular Covid variant.
Being vaccinated against Covid cannot cause you to test positive on either an LFT or PCR test.
When LFTs were first introduced, they were criticised for being much less accurate than PCRs.
However, in October UCL researchers found LFTs were more than 80% effective at detecting any level of Covid-19 infection, which was much higher than previously thought.
LFT results are also more reliable during a period of high Covid cases, because the small number of false positives is much less significant.