WordPress expects every custom post type and taxonomy to use its own permalink format with unique "base". Even if a taxonomy is assigned to a specific post type, such as "Brands" for "Cars", they cannot share the same permalink structure.
WordPress relies on those unique "bases" in its built-in rewrite rules to process permalinks. If more than one content types shares the same URL base, the permalink system cannot correctly identify which content type should be loaded. This leads to URL conflicts and and often results in 404 errors.
With standard permalink settings, there is no direct way to fix this. Permalink Manager offers a straightforward workaround and from the plugin settings, you can set the same permalink base for selected post types or taxonomies, without relying on custom code snippets.
How to Use the Same URL Structure for Custom Post Types and Taxonomies
When reorganizing a website, many site owners try to simplify their permalink structure so that URLs better reflect the intended content hierarchy.
For example, you may want to group all car-related content under
/cars/
. In this case, single car listings could use a structure like
/cars/%manufacturer%/%car%/
, while brand archive pages would be available at
/cars/%manufacturer%/
.
WordPress does not allow this out of the box. With Permalink Manager, you can work around this restriction and set up your URL structures exactly as needed. The example below explains how to configure this setup step by step.
Step 1: Access the Permastructure Settings
You can customize the default permalink structure and assign it to more than one post type or taxonomy using the Permastructures editor.
You can find it in your WordPress admin dashboard under "Tools -> Permalink Manager -> Permastructures". In the editor, you will see a list of available content types.
Each post type and taxonomy has its own settings, so you need to adjust the permalink base separately for each one.
Step 2: Duplicate the Permalink Formats
If you want different content types to share the same permalink base, change the original base slug. For example, replace "manufacturer" with the word "cars". Apply the same change to any other post types or taxonomies that should use this shared base.
Once you finish editing the settings, do not forget to save the changes. Scroll to the bottom of the page and click the "Save Permastructures" button to apply the new permalink formats.
Step 3: Apply Changes to Existing URLs
The updated permalink structure applies only to newly published content. If you want older URLs to follow the new structure as well, you can regenerate them manually. To do this, use the "Regenerate/reset" tool.
The plugin includes a built-in canonical redirect, so old URLs automatically redirect to the new structure, preventing broken links and 404 errors.
FAQ
Why Do I Get a "404 Not Found" Error When Custom Post Types or Taxonomies Share the Same URL Base?
This issue occurs due to how WordPress processes rewrite rules. Rewrite rules determine which content type should be loaded based on the requested URL.
When more than one custom post type or taxonomy uses the same permalink base, WordPress cannot distinguish between them based on the URL alone.
It does not check whether a matching post or term actually exists first. Instead, it picks the rewrite rule with the highest priority, which is usually the taxonomy rule, and tries to find a match there.
For example, if both Products and Product Categories use the same base (e.g.
/products/
), and you open
/products/sample-product/
, WordPress may detect this URL as a product category archive and try to load a product category named "sample-product".
If no such category exists, the result will be a 404 page, even if a product with that slug exists.
Can I Share a Permalink Base Using Custom Code Without a Plugin?
Yes, it can be done, though not in the way you might expect. Some developers try to solve this by registering extra rewrite rules using add_rewrite_rule(), but unfortunately that approach does not work in this specific case.
After saving the permalink settings to flush the rewrite rules, one content type usually works as expected, while the other returns a 404 error.
When two different post types share the same permalink structure, WordPress applies the first matching rewrite rule it finds. It does not continue checking other rules, even if that first match returns a "404" error page.
This is a known WordPress limitation, and it is documented in many WordPress.org support threads like this one. If you prefer not to use an additional permalink plugin, you will need a complex workaround that bypasses the default WordPress rewrite rules.
Permalink Manager handles this automatically and stores each custom permalink separately and uses its own detection logic to match them, without relying on the WordPress rewrite system at all.
Can I Use Permalink Manager For Custom Post Types and Taxonomies Permalinks?
Permalink Manager supports built-in WordPress post types and taxonomies including posts and pages, categories and tags. The plugin also fully supports custom post types and custom taxonomies controlled by 3rd party themes or plugins.
This includes custom post types and taxonomies declared with popular WordPress builders and field management plugins such as WooCommerce, Advanced Custom Fields (ACF), Toolset, JetEngine, and similar tools.
The plugin automatically detects all registered content types, so you can access them in the Permastructures settings and change their permalinks individually.