Please note that the information provided is up-to-date today.
The situation is changing very dynamically, so please carefully observe the messages of individual countries, air carriers and airports.

More information:
gov.pl

Bulgaria: no restrictions (if you were in Portugal, Sweden or Great Britain within 14 days before departure, you are quarantined for 14 days)..

Croatia: no restrictions, but it is recommended to fill in the form at entercroatia.mup.hr .

Cyprus: Cyprus Flight Pass required, completed and printed prior to boarding the aircraft; the form is available at: cyprusflightpass.gov.cy

Greece: wymagany formularz dostępny na stronie travel.gov.gr oraz pobranie odpowiedniego kodu QR minimum 48 godzin przed wylotem.

France: declaration of destination is required, available at gov.pl . The form must be presented when crossing the border.

Spain: form required, available at spth.gob.es and downloading the relevant QR code at least 48 hours before departure.

Ireland: COVID-19 Passenger Locator Form required – available for download from hse.ie, completed in advance of travel and presented at border crossing. 14 days quarantine required.

Malta: no limitations.

Portugal: air traffic with Portugal suspended until 14 July 2020.

Great Britain: Passenger Locator Form required – sent online at https://www.visas-immigration.service.gov.uk not earlier than 48 hours before arrival.
Mandatory 14-day quarantine (with employee exceptions).
From 10.07.2020, the quarantine is to be abandoned for Poland, all 14 British overseas territories and 17 European Union countries.

Italy: PLF form required 48 hours prior to arrival for travel to Sardinia. The rest of the country without restrictions (provided that you have not been outside the European Union, Schengen zone and Great Britain within 14 days before arrival).