Unfortunately not. If you want to check whether or not you've opted out and/or change your registration details you got two options: wait for your next annual canvas to arrive or contact your local electoral registration office.

Contacting your registration office is your best option. Although there's only one 'official' annual canvas registration offices often update the electoral roll every couple of months; you therefore don't have to postpone opting out until you get your next registration form. The sooner you get off the list, the better. If you don't know the contact details for your elections office, you can find them via aboutmyvote.co.uk (a website run by the Electoral Commission).

Once you've opted out you need to make sure you remain opted out. Always double-check the annual registration form and make sure that the tick box that prevents your personal details will be sold is ticked. [ From June 2014 you no longer need to opt out every time you complete the canvas. Instead, you'll remain opted out (at your current address) indefinitely – JB, June 2015]

For information, your annual canvas form will probably show a link to a website (such as registerbyinternet.com) where you can check, update, and confirm your existing details. Currently, you can only do so during the annual canvas. Once the canvas is done you're no longer able to view your details online.

Finally, if you register for the first time or need to re-register because you've moved house, you can print a registration form via aboutmyvote.co.uk. You can either print a blank form or enter all your details online (don't forget to tick the opt-out box as well!) and then print the form. However, it's not possible to submit the form online; apparently this is because it needs to be properly signed.