Our bylaws require “3. An owner … (shall) … i) pay to the Corporation (or if requested to the Manager), when due, all contributions … ” There are details about interest to be charged, similar to your description. (Emphasis added).
Since we moved in (2002), we have paid our ‘contributions’ by direct debit, so we have not incurred a problem for ourselves (except when the management changed and didn’t notify us of a need to update the wording of our D.D. agreement. We fell into arrears, but no interest was charged because the default was not ours).
When the budget is approved annually, we receive a letter from management showing all the ‘contributions’ due by each unit with a request: “Please check the attached schedule of fees to confirm your monthly condominium fee. If you have made prior arrangements to pay your fees via the Pre-Authorized Debit (PAD) plan then you do not need to do anything further to ensure the payment of fees. If you are paying by post-dated cheques, then we will require series of post-dated cheques, each dated on the first day of the month, commencing (insert your fiscal year commencement date). They are to be made payable to (insert your corporation name).”
Then in a text box and bold print: All payments must be received on the 1st of each month, or late penalties will be applied to all overdue accounts. “NO CASH payment will be accepted”.
I suggest that you no longer accept email payments (which can be arbitrarily withdrawn by the bank) and switch to our methods. Of course, some owners will object and default, but then you should assiduously apply the interest charges permitted by the Act and Regulation, even for a short default period. Banks apply a surcharge when cheques bounce; perhaps (after legal advice) you could apply the same concept, not to raise money but to ensure timely payment.