British nationals who wish to marry in Poland must prove that any prior marriages have ended in death or divorce. They must also supply their full birth certificate (not the shorthand version) and apply for a Certificate of No Impediment (zaświadczenie o nieistnieniu przeszkód do zawarcia związku małżenskiego) from British authorities before they will be allowed to legally marry in Poland.
British Embassy in Warsaw
According to the British Embassy in Warsaw, British nationals who have lived in Poland for at least 21 days can go to the British Embassy, Consular Section in Warsaw. This department will be able to issue you with a Certificate of No Impediment so that you can proceed with your marriage.
When you arrive at the British Embassy in Warsaw, you will need to provide supporting documentation such as a valid, unexpired British passport, 2 completed forms, which are the Notice of Marriage Form and Affidavit Form. Divorcees need to also supply a copy of their decree absolute and for widows/ers, the original death certificate will be required. The fee for the Certificate of No Impediment must be paid for in cash or credit card at the time of application.
Further Legal Requirements
Once you have supplied the necessary supporting documentation, you will need to sign a Notice of Marriage form and swear the Affidavit in the presence of a consular officer at the Embassy. Once you have signed the Notice of Marriage, this will be displayed for 21 days. Provided there is no impediment to your forthcoming marriage, you will be issued with the Certificate of No Impediment (in Polish) after 21 days.
British Nationals Living in the UK
If you are a British national living in the UK and you plan to marry in Poland, you can obtain a Certificate of No Impediment from your local Registry Office. However, the Certificate of No Impediment must still be translated into Polish by a Sworn Translator so that it will be accepted by Polish authorities.
British nationals who wish to marry in Poland will need to make sure that they provide all the necessary documentation and sworn statements prior to their marriage. The two most important documents required include their full British birth certificate and a Certificate of No Impediment, which must be translated into Polish.
British Embassy Warsaw