Installment payments can be made as follows:-
Check with installment voucher.
Generally these take two to four weeks receive by mail.
At the teller with no voucher. The teller will set the payee.
The risk is that the teller selects the wrong option. It should be to the installment account. There are no issues if it is paid into the 2018 installment account. Each bank shows their unique naming and CRA payee options. No issues if the payment is used up to pay taxes due. CRA will take the funds from any account that has a balance. Possible issue when there is a credit balance. In that case you will need to ask for the credit balance to transferred to the correct account or issued as a refund.
CRA My Payment
This works for most banks and credit unions. If I recall correctly it does not work for CIBC. You must use online payments. Perhaps that was just for GST Returns Payments on Filing.
For elderly and for those who are not online bill payers, I have a lot of those, it would be helpful to be able to print a payment advice which those clients can take to bank.