Product Taxonomy: How to Structure Your Categories

To build a product taxonomy, group products by what customers call them, give each product one primary category and define useful attributes for every category. Keep your store’s hierarchy separate from the category systems used by Shopify and Google. A shopper looking for a waterproof jacket needs a useful filter, not another branch in a 60-item menu.

Start with a catalogue export and your site search terms. You also need permission to edit product data and collections. On Shopify, storefront filters need a compatible theme. Build and review the mapping before changing published categories, so products keep their correct collection membership.

What a Product Taxonomy Does

A product taxonomy is the hierarchy of product categories plus the attributes attached to each category. Categories describe what a product is. Attributes describe its properties, such as a tent’s capacity or a jacket’s waterproof rating.

The navigation menu displays selected parts of that structure. It can also include sale pages or gift guides, which don’t need to become permanent categories. Changing a menu label alone won’t repair missing product attributes.

Consider this hypothetical outdoor retailer’s three-level taxonomy. The last column lists attributes attached to the lowest category.

Department	Product group	Product category	Category attributes
Camping	Shelter	Tents	Capacity, packed weight, season rating, waterproof rating
Camping	Sleeping gear	Sleeping bags	Temperature rating, insulation, shape, packed weight
Clothing	Outerwear	Waterproof jackets	Size, colour, material, waterproof rating
Hiking	Footwear	Hiking boots	Size, width, upper material, waterproof construction

A two-person tent sits in Camping / Shelter / Tents. Its capacity is an attribute value, so the retailer can add four-person tents without creating another category branch. Use the guide to product attributes to decide what information each category needs.

Design Categories Around How Shoppers Search

Build category names from shopper language and the tasks people bring to your store. Site search terms show the words customers already use. Competitor menus can reveal familiar groupings, but your own range decides which groups you need.

1. Export your current products with their existing categories and attributes. Mark categories that contain the same products under different names.
2. Group search terms by the product customers want. Combine wording such as raincoat and waterproof jacket when it describes the same range.
3. Create broad departments, then useful product groups. Keep most stores to about three category levels as a starting rule.
4. Move properties into attributes. Colour, capacity and material usually belong in filters instead of separate category branches.
5. Try the draft with representative products. Ask someone unfamiliar with the structure where they would look for each item.

After this pass, each group must have a clear purpose and a name customers recognise. Add depth only when the extra category makes a useful distinction within a substantial range. An empty fourth level slows browsing without helping someone choose.

For a menu with 60 entries, inspect repeated groups before deleting categories. Several menu entries can point to one collection. If customers search the right words but receive poor results, use the guide to ecommerce site search for the search configuration.

Product Categorisation Rules That Scale

Give every product one primary category based on its main function, then use secondary collections for other ways customers shop. A waterproof hiking jacket belongs in Waterproof jackets even when it also appears in a winter promotion.

Write down the rules for products that fit awkwardly. Keep these rules beside the taxonomy so different staff make the same decision.

Product situation	Primary category rule	Other browsing route
Several identical products sold together	Use the category of the individual product	Multipack filter or collection
A bundle with one main product and accessories	Use the main product’s category	Bundle collection
A mixed gift set without a dominant product	Use a defined gift-set category	Recipient or occasion collection
A seasonal version of an ordinary product	Keep its functional category	Seasonal collection or tag

Keep a short definition for each category, including what it excludes. For example, Hiking boots excludes trail-running shoes even if both appear in a hiking collection. Assign one person to approve new categories and resolve disputed assignments.

A store can show one product in several collections without creating several copies of the product itself. Keep its product record and primary category stable when you change merchandising campaigns.

Shopify Collections and Filters

Map your store taxonomy to Shopify collections for browsing, then use consistent product data to control membership and filters. Collections can group products by category or by a temporary merchandising purpose.

Shopify’s Help Center describes a new collections model with manual selections and automatic conditions, alongside legacy manual and smart collections. Use the model available in your admin. In the legacy model, staff select products for manual collections, while smart collections add products that match conditions such as tags.

Create one collection for each category that needs a public browsing page. Point repeated menu entries to that collection. For example, both Camping and Gifts for campers can link to the existing Tents collection instead of creating two identical tent pages.

Shopify’s standard product category is chosen from its Standard Product Taxonomy. The free-text product type is your custom label. Set both when the standard category describes the product but your merchandising needs a store-specific grouping, such as Lightweight hiking jackets.

A standard category unlocks relevant category metafields, which hold structured product attributes. Shopify Search & Discovery supports category metafields as filter sources, as well as tags and product options. Prefer structured fields for measured properties such as packed weight.

In Search & Discovery, open Filters, choose Add filter and select the source you’ve populated. Save it, then open the collection in your storefront. Selecting two-person capacity must return only matching tents. If nothing appears, check the product values and theme support. Collections over 5,000 products don’t display Shopify’s storefront filters.

Shopify says product tags aren’t used by search engines. Tags help organise products and can drive collection conditions or customer filters. Adding keyword tags alone won’t improve a product page’s search ranking.

Tag-filtered pages can create thin or duplicate URLs when their product selection adds little useful information. Inspect the URLs your theme generates and decide which category pages deserve indexing. Google’s guidance on faceted navigation explains how filter combinations multiply crawlable URLs. Don’t create an indexable page for every tag combination.

Mapping to the Google Product Taxonomy

Map each store category to the most specific accurate category in Google’s published product taxonomy, with product-level exceptions where a store category mixes different goods. A broad store category such as Pantry needs several Google mappings because olive oil and flour are different product types.

Google Merchant Center assigns categories automatically. The google_product_category attribute is optional. Google’s attribute guidance permits overrides for specified situations, including category-based campaign targeting, incorrect category-specific requirements and alcohol classification.

Keep Google’s category separate from product_type. The latter carries your store’s own category path and helps organise Shopping campaign reporting and bidding. Google’s guidance for product type recommends supplying the full path, with spaces around each > separator.

Use a mapping table with a store category, Google category and an exception rule. For a hypothetical pantry retailer, the store path Pantry / Oils / Olive oil maps to this published Google path:

Food, Beverages & Tobacco > Food Items > Cooking & Baking Ingredients > Cooking Oils

Google’s category list gives Cooking Oils the numeric ID 2126. That is the appropriate leaf for culinary olive oil in this list. Don’t invent an Olive Oil child category or stop at the broad Food Items branch.

To find another mapping, search the published list for the product’s main function, then read its parent categories. A category finder can help locate candidates, but compare its result with Google’s official list before saving the mapping.

In a CSV product feed, the category values sit on the same product row as its ID and title. This example shows the two separate feed columns.

Feed column	Example value
id	olive-oil-500
google_product_category	2126
product_type	Pantry > Oils > Olive oil
title	Extra virgin olive oil 500 mL

Google accepts either the numeric ID or the complete predefined path for google_product_category, not both. Use the ID when your feed connector requires it or to avoid language and path spelling differences. If you supply a path, preserve Google’s wording exactly.

When you leave the field blank, Merchant Center still assigns a category from the product information. Inspect that assignment and use an allowed override if it puts the item in the wrong campaign or triggers inappropriate requirements. See Google’s specification for Google product categories.

A clean mapping also gives an AI shopping agent a stable category label when that data is included in its catalogue. Category mapping supports product grouping. Accurate attributes still determine whether a product matches a request such as a lightweight two-person tent.

Use AI Product Tagging With a Review Step

Use AI to propose categories and tags against your approved taxonomy, then review the suggestions before applying them in bulk. Give the tool the allowed category paths, tag vocabulary and edge-case rules. Require it to flag an unclear match instead of creating a new category.

1. Generate suggestions in a separate working file. Keep the current values beside the proposals so you can compare them.
2. Review a sample from every category, including bundles and mixed gift sets. Check all flagged products and unfamiliar category assignments.
3. Correct systematic errors before importing anything. If the tool mistakes insulated jackets for waterproof jackets, fix that rule and regenerate the affected group.
4. Apply the reviewed batch, then inspect collection membership and filters. Confirm the Google feed still has valid mappings for the changed products.

Watch for vocabulary drift after the first import. Water-resistant and waterproof describe different properties, while navy and navy blue can be duplicate colour values. Keep an approved value list and review new values when staff or suppliers add products.

A spreadsheet suits a catalogue that one person can maintain with manageable exports. Product taxonomy software or product information management (PIM) becomes useful when thousands of products feed several channels and category changes need controlled approval. There’s no universal product-count threshold. The deciding cost is repeated correction across exports, especially when multiple staff edit the same data.

Before using the new taxonomy across your catalogue, follow one ordinary product and one edge case from their record to the storefront and feed. Both must appear in the intended collection, match the correct filters and retain the expected Google category. Expand the rollout only after that path works.