When setting up this Canada Post plugin, there are a few things to check if you are not getting shipping rates in the cart or checkout.
1. Check the entered Canada Post API Production credentials. Click “Validate Credentials” button to know that this is working.

2. Make sure you’ve added “Canada Post” method a Woocommerce Shipping Zone. For example, add it to the “Locations not covered by your other zones” shipping zone.

3. Ensure some services are selected (ie. Xpresspost, Expedited, etc).

4. Ensure the Products in Woocommerce have Shipping Weight and Dimensions entered for them.

5. In the plugin settings, try to disable “Shipping Class Rules” if you’ve got them enabled.

6. Check the “Rates Lookup Logging” feature—this will tell you what is being calculated in the checkout—and whether the plugin was able to get rates for the cart.

If the price for the rate is too high, it can be because of the calculated package size.

• Look to see if the Product has “Ship Separately” selected on it. This selection can be found on the Product edit page in the Shipping tab. This will keep the product from being packed together and will result in a higher rate when multiple items are in the cart, because the rate will be as if the products are shipped separately.
• Look to see what the “Rates Lookup Logging” area displays, what package size and weight was sent to the Canada Post Api for the rate.
• This plugin uses the dimensions to calculate the “Volumetric” weight which is used if it is higher than the actual weight. This can be turned off with the option “After packing, use Volumetric weight”. It will still use the dimensions when packing and determining if an item will fit in flat rate services, but it will use the actual weight for the rate lookup.
• Look to see if you have boxes defined—this will increase the size of the package if you don’t have small enough boxes defined for the product. You can uncheck “Enable Boxes” if you want to just let the plugin generate the package size for the packed items

If you want Commercial/Contract Rates enabled, just enter your contract account number into the “Commercial/Contract” in the plugin’s settings. This will give you commercial prices and enable shipment labels for contract accounts.

You will need to add Canada Post to a Shipping Zone. (This feature exists in Woocommerce 2.6+ If you are using a previous version of Woocommerce, you do not need to worry about this). Also, ensure you have updated this Canada Post plugin to at least version 1.5.7+ (If you’re not sure, just update the plugin to the current one available as a download in your CodeCanyon downloads page).

Steps to Add Canada Post:

1. Go to the Shipping Zones page (Woocommerce > Settings > Shipping (tab).
2. If you want Canada Post for any area, click on the “Rest of the World” Shipping Zone.  If you want Canada Post for only a specific zone, click on the zone(s) that you want to add Canada Post to.
3. Click “Add Shipping Method” button (bottom right). Then Select “Canada Post” from the dropdown.

That’s it! Now Canada Post will be an active shipping method.

Screenshots of setting up the Shipping Zone

Initially, your Shipping Zone page will look like this. Scroll down and click on the “Rest of the Word” shipping zone. Then click the “Add Shipping Method” button Then Select “Canada Post” You’ll see “Canada Post” Enabled in the “Rest of the Word” shipping zone.

That’s it!