How to create custom post types in WordPress

Decide what the content represents and whether it really needs its own post type. Use a custom post type for a distinct content type such as Books, Courses or Case Studies, rather than creating one for a small variation of a normal post.

Choose a short, lowercase machine name such as book. The post type key must be no more than 20 characters and should not clash with a reserved WordPress term. Keep the public URL slug separate from the internal key if you need a different URL.

Put the registration in a site plugin or must-use plugin, not only in the theme. That keeps the content type registered when you change themes. Hook the registration to WordPress's init action and call register_post_type() with labels, visibility, archive behaviour, URL settings and editor features.

A minimal pattern looks like this: add_action( 'init', 'my_site_register_books' ); function my_site_register_books() { register_post_type( 'book', array( 'labels' => array( 'name' => 'Books', 'singular_name' => 'Book' ), 'public' => true, 'has_archive' => true, 'show_in_rest' => true, 'rewrite' => array( 'slug' => 'books' ), 'supports' => array( 'title', 'editor', 'thumbnail', 'excerpt', 'revisions' ) ) ); } Use a unique prefix for your function name. The supports list controls features shown in the editor, while show_in_rest allows the post type to work with the block editor and REST API.

Register a taxonomy when entries need grouping or filtering. Use register_taxonomy() for a category-like hierarchy or a tag-like, non-hierarchical set of terms, and associate it with your post type through the registration arguments or the appropriate object-type connection.

Custom fields are stored as post metadata. WordPress can expose its basic custom-fields interface, but a useful editor experience often needs a field-management plugin or additional meta-box code. Do not confuse a taxonomy with a custom field: taxonomies are for terms shared across many entries, while fields hold values belonging to one entry.

Your new entries can initially fall back to the theme's normal templates. For a classic theme, add single-book.php for an individual entry and archive-book.php for the post type archive. For a block theme, use the corresponding templates in the theme's templates area, or design them in the Site Editor when supported.

WordPress checks the post-type-specific template before falling back to broader templates such as single.php, archive.php or index.php. Create a specific template only when the new content needs a different layout.

After registering the post type, visit Settings > Permalinks and save the settings once. This rebuilds WordPress's rewrite rules and commonly fixes a new post type archive or single URL returning a 404.

If the post type is registered by a plugin, flush rewrite rules on plugin activation and deactivation rather than on every page load. Flushing on every request adds unnecessary work and can cause problems on busy sites. Also check that the rewrite slug does not conflict with a page, taxonomy or another post type.

The fast route is to install ACPT, create the post type from its visual interface, then add the fields, taxonomies, templates and permissions you need. This avoids writing and maintaining the registration code, which is useful when several content types or complex field groups are involved.

The manual route is still a good choice for a small, stable site feature that belongs in your site's own plugin. Use ACPT when you want to configure the structure quickly, give editors a clearer interface, or change the content model without editing PHP.