For the same value of package, we have had customers who never had to pay for any custom fees, and we have had customers who had to paid for it. It depends on the Canada, UK custom department.
If you did, DHL/Fedex would have sent you a notice stating that your package couldn't be delivered (our experience is that they don’t always tell you the reason).
Please use the link below and check the status of the mail.
https://www.dhl.com/us-en/home/global-forwarding/help-center/freight-shipping-faqs.html
Put your tracking number in, and you would be able to see the most updated status of your package. The status should say “Held with fee to pay”.
Please click “Pay your fee online now”. It will allow you to pay the fee online. Once you pay the fee, the package will be released by the custom.