This setting allows you to control how shipping rates are combined when applicable.

Yes (Automatic): All product based rates (such as Product, Tag, SKU, Product Type, Vendor, etc.) will be automatically combined into a single shipping rate.

This option ensures that if multiple matching rules apply to items in the cart, the rates will be merged seamlessly without needing manual configuration.

Example:

Let’s say you have the following product based shipping rules:

Product A → $50 shipping rate

Product B → $30 shipping rate

If Yes (Automatic) is selected:

A customer adds Product A and Product B to the cart.

The shipping rate shown at checkout will be $50 + $30 = $80

No (Manually – Using merge rate): You can manually merge rates.

Merge Default Rate with Product-Based Rates

If you enable this, default rates (like weight-based) will mix only when some products in the cart don’t have a product-specific rate.

Additional Description of Mix Rate (optional):

Add a custom label to help customers understand that this rate is auto-added.

Maximum Price of Auto Product Base Mix Rate (optional):

Sets a cap on the extra charge added from this mix.

Example: If calculated mix is $100 but you’ve set maximum rate to $80 then rate will be $80.

Merge Shipping Rate Manually

Step 1: Dashboard > Shipping > Merge Rates

Step 2: Click button Add Merge Rate

Step 3: Give the name for internal use

Step 4: Choose the condition for merge rate. 

1. ALL rates must have at least one tag: Merge only if every matched rate has a tag.

2. ANY rates found with tag: Merge happens if at least one rate has a tag.

Step 5: Merge Rate Price Calculation

1. SUM of the values: All matched shipping rates will be added together.

2. AVERAGE of the value: Takes the average of all matched rates.

3. LOWEST of the value: Only the lowest matched rate will be applied.

4. HIGHEST of the value: Only the highest matched rate will be applied.

5. MULTIPLY of the values: All matched shipping rates will be multiplied together.

Step 6: Add tags which you’ve added in the rates.

You can also exclude the rates which you don’t want to merge.

Minimum & Maximum Shipping Rate (Optional)

1. Minimum Shipping Rate:

Ensures the final merged rate doesn’t go below this value.
Example: If merged total is $40 and minimum is $50 → Final rate = $50

2. Maximum Shipping Rate:

Caps the final rate to not go above this value.
Example: If merged total is $600 and maximum is $500 → Final rate = $500