As per UK Border Agency website, as a permanent resident of Canada you can transit (airside) without visa even if you are from a DATV country.
I'm from a DATV country, I was given permission to land at Heathrow for 24 hours without visa before. I'm going through London again I'm wondering if things have changed.
After arriving did you apply to enter to the UK? Or did you just asked someone about transiting they detained you?
'Transit without visa' concession - DATV exemptions
If you are a national of a country covered by the DATV system, you may be able to transit the UK airside without a visa. To qualify for this exemption:
you must arrive and depart by air; andyour onward flight must be confirmed, and must depart within 24 hours; andyou have proper documentation for your destination, including a visa if necessary.Additionally, you must hold:
1) a valid entry visa for Australia, Canada, New Zealand or the USA, and a valid airline ticket for travel via the UK, as part of a journey to or from one of those countries; or
2) a valid airline ticket for travel via the UK as part of a journey from Australia, Canada, New Zealand or the USA, if you are transiting the UK no more than 6 months after the date when you last entered Australia, Canada, New Zealand or the USA with a valid entry visa for that country; or
3) a valid USA I-551 permanent resident card issued on or after 21 April 1998; or
4) an expired I-551 permanent resident card issued on or after 21 April 1998, accompanied by an I-797 extension letter issued by the Bureau of Citizenship; or
5) a valid Canadian permanent resident card issued on or after 28 June 2002; or
6) a valid Australian or New Zealand residence visa; or
7) a valid uniform format category D visa for entry to a state in the European Economic Area (EEA); or
8) a valid uniform format residence permit issued by an EEA state under Council Regulation (EC) number 1030/2002; or
9) a valid UK residence card; or
10) a valid EEA family permit issued by the UK government; or
11) a diplomatic or service passport issued by the People's Republic of China; or
12) a diplomatic or official passport issued by India; or
13) a diplomatic or official passport issued by Vietnam.
A valid US immigrant visa packet (form 155A/155B) is a 'valid visa' for these purposes, but the following documents are not valid for the DATV exemption:
an I-512 parole letter or an I-797C (notice of action) instead of a valid US visa.
a transportation letter instead of a valid US permanent resident card issued on or after 21 April 1998;
a valid travel document with a US 'ADIT' stamp saying - 'Processed for I-551. TEMPORARY EVIDENCE OF LAWFUL ADMISSION FOR PERMANENT RESIDENCE VALID UNTIL [date]. EMPLOYMENT AUTHORIZED'; and
a US visa foil endorsed, "NOT A VISA. FOIL PREPARED AT DHS REQUEST".
If you are a national of a DATV country and you hold a non-national (including refugee) travel document, you will need to get a DATV to transit the UK airside unless you qualify for one of the exemptions listed above.
Please note that this concession is operated at the UK Border Agency's discretion. Our officers may therefore prevent you from using the concession. If you are unsure whether you meet the concession's criteria, you should get a visa before you travel.
As part of your application, you will need to enrol your fingerprints and facial image (known as 'biometric information') at a visa application centre.
Select your country in our country finder to find out:
how to apply in your country (including how to apply online);the location of our visa application centres;
how long we generally take to process visa applications; and
how your documents will be returned to you.
If your application is successful, you can find information about what will happen at the border (including customs requirements) in the Customs and travel information section.
I'm from a DATV country, I was given permission to land at Heathrow for 24 hours without visa before. I'm going through London again I'm wondering if things have changed.
After arriving did you apply to enter to the UK? Or did you just asked someone about transiting they detained you?
'Transit without visa' concession - DATV exemptions
If you are a national of a country covered by the DATV system, you may be able to transit the UK airside without a visa. To qualify for this exemption:
you must arrive and depart by air; andyour onward flight must be confirmed, and must depart within 24 hours; andyou have proper documentation for your destination, including a visa if necessary.Additionally, you must hold:
1) a valid entry visa for Australia, Canada, New Zealand or the USA, and a valid airline ticket for travel via the UK, as part of a journey to or from one of those countries; or
2) a valid airline ticket for travel via the UK as part of a journey from Australia, Canada, New Zealand or the USA, if you are transiting the UK no more than 6 months after the date when you last entered Australia, Canada, New Zealand or the USA with a valid entry visa for that country; or
3) a valid USA I-551 permanent resident card issued on or after 21 April 1998; or
4) an expired I-551 permanent resident card issued on or after 21 April 1998, accompanied by an I-797 extension letter issued by the Bureau of Citizenship; or
5) a valid Canadian permanent resident card issued on or after 28 June 2002; or
6) a valid Australian or New Zealand residence visa; or
7) a valid uniform format category D visa for entry to a state in the European Economic Area (EEA); or
8) a valid uniform format residence permit issued by an EEA state under Council Regulation (EC) number 1030/2002; or
9) a valid UK residence card; or
10) a valid EEA family permit issued by the UK government; or
11) a diplomatic or service passport issued by the People's Republic of China; or
12) a diplomatic or official passport issued by India; or
13) a diplomatic or official passport issued by Vietnam.
A valid US immigrant visa packet (form 155A/155B) is a 'valid visa' for these purposes, but the following documents are not valid for the DATV exemption:
an I-512 parole letter or an I-797C (notice of action) instead of a valid US visa.
a transportation letter instead of a valid US permanent resident card issued on or after 21 April 1998;
a valid travel document with a US 'ADIT' stamp saying - 'Processed for I-551. TEMPORARY EVIDENCE OF LAWFUL ADMISSION FOR PERMANENT RESIDENCE VALID UNTIL [date]. EMPLOYMENT AUTHORIZED'; and
a US visa foil endorsed, "NOT A VISA. FOIL PREPARED AT DHS REQUEST".
If you are a national of a DATV country and you hold a non-national (including refugee) travel document, you will need to get a DATV to transit the UK airside unless you qualify for one of the exemptions listed above.
Please note that this concession is operated at the UK Border Agency's discretion. Our officers may therefore prevent you from using the concession. If you are unsure whether you meet the concession's criteria, you should get a visa before you travel.
As part of your application, you will need to enrol your fingerprints and facial image (known as 'biometric information') at a visa application centre.
Select your country in our country finder to find out:
how to apply in your country (including how to apply online);the location of our visa application centres;
how long we generally take to process visa applications; and
how your documents will be returned to you.
If your application is successful, you can find information about what will happen at the border (including customs requirements) in the Customs and travel information section.