Canada Post services are either tracked or not trackable.
No number can be 'added'.
A letter sent BC to NL can cost as little as 85 cents, untracked.
To track it using Registration would be $18.35.
More usefully a LetterPost item weighing less than 100 grams can be sent to the US for $2.95. A Tracked Parcel would cost $33.25.
Tracking is Seller Protection against unwarranted claims of non-delivery. Many Canadian sellers do no track lightweight, compact and inexpensive items because the postal system does a very good job of fast and secure delivery and most buyers are honest.
https://www.canadapost.ca/cpotools/apps/far/business/findARate?execution=e1s1
And surprise! Canada Post has the answer for most of your shipping questions. Whooda thunk?
