Canonicalization interact with 301 redirects?

[Towelsrus]

This is a interesting one I think.

I have recently taken down some product list pages from our website www.towelsrus.co.uk. These have canonicalisation in place to deal with pages where a query string is generated depending on the search criteria.

When I put a 301 redirect in place the target page redirects fine, however webmaster tools then errors with 404 on all canonicalised pages.

Is this correct behaviour and how do we get over this?

[TextMarketing]

If I'm understanding this right, you need to update your canonical tags with the pages the 301 is redirecting to.

[MikeRoberts]

I'm not 100% sure why its throwing 404s because I've never had that exact problem when doing the same thing on any sites I work on but I agree with TextMarketing on updating the canonicals. If you originally had Page 1, Page 2, and Page 3 canonicalized to Page A and now Page A has been 301'd to Page B, you should update Page 1, Page 2 and Page 3 to have their canonical tags pointing to Page B instead of the 301 page.

[Towelsrus]

Thanks chaps. The other issue it also flags up is duplicate data as now no canonicalisation is in place. double whammy. I'll get the web company to allow us to update these for the future.

[MikeRoberts]

Just remember that a canonical is a signal not a directive. Google and other search engines can choose whether or not to listen to your signal. So make sure those "duplicate" pages need to exist as they are currently. In some cases it may make more sense to either update the page with fresh, original, and relevant content or to have the page marked NoIndex depending on the situation.

[Dr-Pete]

If I'm (we're) understanding your situation correctly, then I'd have to agree with Mike. You should 301-redirect all of the versions, not "chain" the canonical to a 301. That's going to produce very unpredictable results at best.