Canada Post requires you to generate a manifest for your packages. Canada Post Manifests are electronically generated within OrderCup and transmitted to Canada Post. Only contract customers of Canada Post are required to generate manifests.

Here is how the Canada Post Manifest generation works in OrderCup:

Once you are done generating the shipping labels for your packages for the day, click on the Canada Post Manifests button on the Packages tab.   This will load a overlay with packages that have not been transmitted to Canada Post for manifest generation via OrderCup. All the packages on this page are selected by default.

You can then un-select the packages that you want to exclude from the manifest. For example, you may want to exclude packages for which you have generated labels, but do not want to ship yet.

Once you are done with selecting the exact packages you want to include on the manifest, click Transmit Shipments link. This will actually transmit your selected packages to Canada Post. This process takes some time and you need to wait patiently till the loading dialog disappears. Note that you need to do a Print Manifest before you do a Transmit Shipments again.

After the Transmit Shipments is completed you can print manifest for the currently transmitted shipments by clicking Print Manifest. This will generate a manifest and in response you will get back the printable PDF Manifest document that you will need to hand over to the Canada Post driver picking up the packages. Note that Print Manifest works only if you have done a Transmit Shipments

The Reprint (last manifest) link just allows you to re-print the printable PDF file of the last generated Manifest. You can use Canada Post Manifests --> Reprint (last manifest) in case you need to access the PDF Manifest document created by the last Print Manifest request.

Note that manifest generation is a relatively slower process on the Canada Post side and the time taken increases proportionally with the increase in the number of shipments being transmitted.  If you get an error response after you click generate saying: "9153 Error: The transmit process has not completed yet. Please try again later.", kindly click the Reprint (last manifest) link again after a couple of minutes and it would return the manifest for the shipments transmitted recently if the transmit was completed on the Canada Post side by then. If the transmit is still not complete on the Canada Post side you would get a previous manifest, so make sure you have the recent one or click Reprint (last manifest) again after a couple of minutes.

You do not need to electronically submit the manifest file to Canada Post's e-system. Its already done when you have done  Transmit Shipments & Print Manifest

Note: As a general guideline, you should generate manifests regularly (daily) for the packages you ship via OrderCup.