The canonical code within WordPress should actually already redirect those old posts to the new posts automatically. Have you tested that?
Related Posts:
- Custom permalink structure leads to be 404 on pagination
- How to get permalinks with category base working with sub-categories
- Catch 404 after changing permalink structure from /%postname%/ to /%category%/%postname%/
- Archive pagination causing 404 with permalinks structure
- New categories are now going to 404s
- WordPress subcategories return 404 in custom template
- Redirect category to url with /category
- Changing permalink from /postname/ to category/postname/
- Same base for category and post
- Sub Categories Keep Redirecting to Pages With Same Slugs
- Redirect single article permalink to paginated category page
- Category url generate 404 error
- Custom Permalink with child categories creating 404
- Pagination breaks on child-categories, works fine on parent-category
- Subcategory Page 404ing
- Custom permalink /%category%/%postname%/ produces 404 on each post
- WordPress Category url redirects to subdomain
- Catch 404 after changing permalink structure from /%postname%/ to /%category%/%postname%/
- htaccess redirect for all categories converted to tags now showing 404
- How to remove category from wordpress url?
- How to create a custom url for a category [closed]
- How to change the category in URL for posts in multiple categories?
- Multisite blog converting categories to subdomains
- How to get the url to tag & category base set by the user?
- How to: 301 Redirect /category/ to /customname/
- How to? Redirect /category/sci-fi/ to /category/scifi/?
- How to Include the Parent and Child Category in the Permalink if the Post is Added to Both
- Redirecting category link to first child post
- Root level category, tag, author and archive pages to work
- Categories and Tags returning 404 on the sidebar when using ugly permalinks
- Plural Category Base Slug On Category Archive Page
- Redirect old permalinks with Month and name to Post name on new site
- WooCommerce change category url and product base
- Removing category base form links messes up the parent-child behavior
- Redirect category to first available child post
- Remove Parent Category from Child Category URL
- How to set up Author archives with sub category URL
- Allow dot in wordpress permalinks (only for categories)
- How to Filter categories in the permalink structure
- Specifying multiple categories in URL (permalink)?
- Should the actual /category/ directory be 404? Is that normal WP behaviour
- Add “page-a” slug to category link if user visit category link from “page-a”
- Changing the post date without causing 404 error
- One Specific Category To Permalink
- Category being displayed without base parmalink
- wordpress sub-category ( lowercase letters + non-latin characters ) = 404
- Removing post category base giving Error 404
- Redirecting thousands of posts that currently have no category in their permalink when changing permalink structure to include category
- WP didn’t redirect to canonical category URL
- Permalinks: display just one kind of wp category in the posts url
- Multiple URL’s based on category for one post
- category permalinks
- Remove the parent name from permalink
- Resolve 404 on posts without category
- How to add a post without assigning to a category?
- WordPress alphabetical A-Z custom post type post result display
- Hierarchical permalink structure for posts showing categories and sub-categories
- Use the category name instead of category slug in permalinks
- Cannon see subcategory in permalink
- Redirect Changed Permalink on wordpress
- Custom page category taxonomy 404
- How do I change the category permalink structure?
- How to display post in custom file not in archive file?
- Category link redirect to custom template page instead of index.php?
- Advanced permalinks structure
- Is the part “category” fixed to an URL to an archive or post?
- Categories show 404 error on multisite installation
- Subcategory Page URL to Display Only Posts from that Subcategory?
- Using custom structure prefix showing 404 for sub-categories
- pagination 404 error, same slug home and categories
- How to add tags under categories
- OK to redirect the root WordPress category slug?
- How to set the same base url for two different taxonomies?
- Get multiple category names from permalink
- Get category base permalink
- Extending page urls without getting a 404
- Category URL’s 404 after setting category base to ‘.’
- Include a page’s “category” in its URL
- Wrong category in URLs accepted like the correct one
- Remove base category gives 404 error
- Change Category Base For Custom Post Type or Posts Page
- WordPress pagination not working because of subcategory
- same permalink for parent category and child category
- /blog/ permalink prefix causes category pages to 404
- Create monthly archive for parent category
- Page Type with Category Link
- Most efficient use of custom taxonomies, categories, and pages
- Removing short versions of category archive URL
- Page redirecting to category (IE only)
- Change next_post and previous_link to navigate throught parent categories only
- Using pagination with multiple loops causes it to break
- how wordpress generates permalinks as /%category%/%post%/
- WordPress category gives 404 after moving to a different domain
- Create custom Perma link
- Multiple Parent Category URLs
- Custom EndPoint not working when strip child category in URL
- Remove “?category=” in the URL wordpress ajax filter work for category
- How to add custom prefix before category base for category page URL?
- Category Redirection Problem
- How to remove the category from the url only for a specific category of articles on wordpress