does my mom need transit visa for layover london? (Canada visitor visa) Please response

[supergirl007]

I am planning to book tickets for my mom, do you guys know any country which allows transit without a visa?

My mom has a Canada visitor visa. I have checked the official website of the UK, I am confused.

 

[vishalv]

Usually if you have a Canadian visit visa and a connecting flight to Canada, you don't need a transit visa.

Do check in the following official link & you should be able to get additional confirmation.
https://www.gov.uk/check-uk-visa