EFT stands for Electronic Fund Transfer - it is the backbone of the Canadian payment industry. When you trigger an add funds request, EFT removes the funds from your account and sends the payment to someone else. It also automatically verifies that you have enough funds.
If you have insufficient funds in your account at the time of withdrawal (not at the time of request), the EFT won’t work.
It takes 2-3 business days for the funds to be removed from your account. Ensure you keep enough money in your account to cover all EFT request to avoid unnecessary NSF charges. It can take up for 7 business days depending on your bank for the funds to fully clear.