PastExpiry, you have to complete a PMG submission form correctly (ID each note/ est value, etc) & organize your notes exactly like your submission form. At a Canadian P.O., you will give them info for your declaration form once (or before) you pay for the postage.
There are 2 ways to submit: first by becoming a member (which is how I answered the question- as a member) or by submitting through an authorized dealer. A member must pay an annual fee but if you submit a 50 note bulk batch (like I did) & your notes aren't off-the-chart rare (like mine) it can be the rate I mentioned + your fees.
Also, the World bulk rate is lower than the US bulk rate & if you submit under 50 notes (non bulk rate) it is much higher again. They also have a system of tiers- which I believe is more about the insurance involved. If your note is a 1914 $50 Red seal, then its like you're sending in the "crown jewels" & as such will be charged a higher rate. When you submit through a dealer even low-valued notes could be $100/note @john100.
I believe the same would apply if I were to send in a 5 Balboa from Panama. Instead all of my notes were dated post-1957 & qualified for the world bulk rate.
Check the PMG site:
https://www.pmgnotes.com/submit/how-to-submit/ Like I have written on my first reply: it is not cheap. If you're in Canada & you wish to have BoC notes certified, it is far more economical to use BCS (hands down) since there's no tier system, you have the option to drop them off (if you're in southern ON) & the only extra damage is the GST (which is minor if you factor in the exchange rate with the USD). The only reason I turned to PMG was b/c BCS does not certify World currency.