From 29 July fully vaccinated people coming to the Bailiwick of Guernsey will need to provide proof of a negative test before travelling.
On 1 July testing on arrival ended for fully vaccinated travellers from the Common Travel Area (CTA).
The move comes after community concerns and rising cases in close jurisdictions - including Jersey and the UK.
The director of Public Health said PCR tests and certain supervised lateral tests would be accepted.
Dr Nicola Brink said they had considered the accessibility and costs of the tests in their decision.
She said limiting the tests to PCR tests would mean people having to travel further to get a test and potentially putting themselves at a greater risk of infection.
Dr Brink gave the example of someone in London needing a 50-minute journey on public transport to access a PCR test or just a five-minute walk for a location that offers supervised lateral flow.
She said the supervised lateral flow tests in the UK could be found for £30-40.
More details are due to be released on Tuesday.
Fully vaccinated travellers from Jersey already have to provide a negative test result before travelling.
Others - anyone not fully vaccinated and those who start their journeys outside the CTA - aged over 12 are subject to a test and isolate system based on the level of Covid in the places they have travelled.
Deputy Peter Ferbrache, Chairman of the Civil Contingencies Authority, said: "Many of you are very uneasy about Covid cases coming into the bailiwick and that's put a strain on our relationship with you.
"We tried to address that and say we're doing everything we can, but we've got to be proportionate.
"Our vaccination levels now are very high and they are high enough now that the impact on cases is less, the risk to the community is less and we cannot justify preventing travel in the way we used to."
He said the key was striking the balance between "not letting Covid running riot" and "blanket restrictions".