Both Jersey and Guernsey developed systems to categorise passengers arriving into the Bailiwicks, which determine whether or not they need to isolate.
As the islands' coronavirus vaccine rollouts gather pace, these systems are due to be reintroduced in the coming months as the islands' governments look ahead to a summer with easing restrictions.
In Jersey, travel guidance is issued using a 'traffic light' system, which categorises countries, and in some cases regions, as red, amber and green as shown on this interactive map:
Currently, ALL regions are classified as 'red', meaning inbound passengers must self-isolate for ten days with coronavirus tests on arrival, day five and day ten.
However, the regional classification is due to be reintroduced on 26 April for areas within the British Isles. It will then be applied to international travellers - except those on the 'banned list' - from 17 May.
The system will operate as follows.
Green - Passengers arriving with a green status are required undertake a PCR test on arrival (day zero), day five and day ten, and must isolate until they receive a negative result from their day zero test.
Amber - Passengers arriving with an amber status are required to undertake a PCR test on arrival (day zero), day five and day ten, and must isolate until they receive a negative result from their day five test.
Red - Passengers arriving with a red status are required to undertake a PCR test on arrival (day zero), day five and day ten, and must isolate until they receive a negative result from their day 10 test.
People arriving in Jersey are classified according to the place they have stayed overnight which is considered the highest risk in the past 14 days.
For the full list of country classifications, visit the Government of Jersey's website.
The 'Bailiwick Bubble' has fully reopened with Guernsey's move into Stage 3 of the lockdown exit strategy - meaning islanders can travel between Guernsey, Sark, Alderney and Herm without restriction.
However, restrictions remain in place for travel across the water. While non-essential travel is permitted, meaning the Essential Travel Permit is no longer required, passengers remain subject to a mandatory 14-day isolation period.
In Guernsey, travel guidance is set to be reintroduced on 30 April as follows.
Category 1: This applies to regions and countries where the Bailiwick operates an 'air bridge'. No countries will currently fall into this category after the arrangement between Guernsey and the Isle of Man was suspended.
Category 2: This covers regions with a low prevalence of Covid-19 (between 0 and 30 cases per 100,000 people). Passengers will be required to take test on arrival and self-isolate until they get their results. They would then be subject to 'enhanced passive follow-up' until a second test on day seven. If this returns a negative result, they would then be subject to the 'passive follow-up' stage.
Category 3: This applies to countries and regions with a prevalence rate of between 30 and 100 cases per 100,000 people. Passengers can choose to to take a test and then self-isolate until their second test on day seven. If this returns a negative result, they would then be subject to 'enhanced passive follow-up' until day 14.
Category 4: This applies to countries and regions with a prevalence rate above 100 positive cases per 100,000 people. Arriving passengers must take a test on day of arrival and self-isolate for 14 days.
Guernsey's government is hopeful that travel will be able to resume fully without the need for quarantine from 1 July 2021, with just the requirement of testing on arrival. However, this date is subject to change.