Is it suspicious to send $10K via Interac e-Transfer by dividing it into 4 transfers of $2.5K each?
If the bank decides that you are "structuring" your transactions to avoid going over a reporting limit, they can report all the transactions as suspicious. Whether they do so is a subjective decision up to the bank. For example, if you are a pizza parlor that has been doing business with them for 30 years, they would probably not report it as suspicious. If you are a new customer with no other obvious legitimate business transactions, then they might report it. It's up to them. With larger sums of money, it is generally recommended to use EFT transfers rather than Interac. Interac is intended for transfers below the stated limits.