Those who fail to quarantine after returning from abroad may face a fine of £1,000, the Welsh Government has announced.
New UK Government regulations coming into effect today (June 8), require visitors and residents entering the UK to self-isolate for 14 days - the period of time it can take for symptoms of coronavirus to appear.
This includes UK citizens returning from holidays to Europe.
The regulations also require travellers to provide contact details, the address where they will self-isolate and other information that will support contact tracing.
This must be submitted via an online form and presented on arrival in the UK.
Those who breach of the self-isolation requirement could face a fixed penalty of £1,000.
Meanwhile, failing to provide information in Wales can incur a fixed penalty of £60, rising on each subsequent failure to provide information up to a maximum of £1,920.
The Welsh Government said these measures will contribute to UK maintaining an overall R-rate below one, and mitigating the associated impacts of increased transmission on the NHS and wider economy.
Though the quarantine requirement is an issue of border security, which is not a devolved power, First Minister Mark Drakeford said its implementation required the Welsh Government to put rules through the Senedd.
However, he said it's an issue of public health, and will therefore be pursued by Public Health Wales.
Speaking at the Welsh Government coronavirus briefing on Monday, he said: "The rules of quarantine are pretty tough.
"That's a big ask of people visiting or returning, so they need to know why we are asking them to do it."
He said public health mechanisms will be used to ensure people are adhering to the requirements, including by posting a letter to the address they provided upon entry in the UK.
"We will write to those people through Public Health Wales in a way that requires them to sign for that letter so we know they have arrived there," Mr Drakeford said.
