Having made some changes to your wordpress permalinks, you can easily protect your web site traffic, SEO and search results from Google. This means you and your visitors get no 404 not found error.

This wordpress plug-in looks at the incoming link URL structure and then redirects on the fly to the correct post with the new permalink structure.

This didn’t make my list of Top 9 WordPress plugins for a new install - but if you are migrating a website this is critical.