Pro-rata means that dividing the total number of invitations available is divided into the number of months, to make sure that an equal number of invitations are available every month. Example: Pro-Rate Let's say that for ‘Software Engineers’ job, Australia plans to issue about 15000 invitations from July to June. Then, they will divide the 15000 by 12 to reach the number of 1250 per month. So, they will restrict issuing invitations to the ‘Software Engineers’ category to about 1250 per month. This is just an example to explain pro-rata. An actual number of invitations may be different.