'It's an ugly way to advertise': Natalie Tran spoke out after being sent a letter from AAMI. Credit:James Brickwood In a smaller font, the letter includes the phrases "It's easy to switch" and "switch now". "So why not take up this offer to switch your CTP Green Slip to AAMI and keep it all in one place?" the letter says. Ms Tran posted a photo of the letter to Twitter on Monday afternoon, along with a scathing assessment that it was a "poor and disgusting practise".

"Here's an "ad" sent to me by AAMI for a car my partner owns (not me) that looks EXACTLY like a bill," she wrote. "How is this legal? People must be unknowingly paying bills that are ads. There's a due date and everything. "I don't own the car and my partner doesn't use AAMI for his CTP. "I was about to pay it because I didn't think and saw it as a bill. My poor parents get these too. It's an ugly way to advertise."

In a statement to Fairfax Media, a spokesperson for AAMI said the letter was sent "to make things easier for customers", with its design approved by the NSW Government. The spokesperson said the offer to switch was "clearly stated in the opening paragraph of the notice". "This offer is sent to existing AAMI customers in the form of a regulator-approved policy notice (or Green Slip) in order make it easier for them to immediately obtain Compulsory Third Party (CTP) insurance without any additional steps," the spokesperson said. "The offer to switch includes a personalised CTP quote in the form of a Green Slip. It is sent when their vehicle registration is due. "The NSW Government CTP regulator, SIRA, establishes guidelines for the design of CTP certificates so they can be used as valid Green Slips."

The spokesperson said the design was "the official certificate used for all AAMI CTP Green Slips, including new policies". "This is done to make things easier for customers. If the offer was in a different design (ie not a valid Green Slip), the customer would have to go through the additional step of requesting a new CTP policy be created," the spokesperson said. "We have been sending out notices like this for many years as a service to our valued customers. We are not aware of any similar customer complaints received during this time." However, AAMI's explanation did not seem to satisfy Ms Tran. Responding again on Twitter, she wrote: "So just an excuse for an offer purposely formatted to look like a bill... due date, policy number, details, everything? Come on."

Her frustration seems to be shared by others, with one eerily similar complaint about the letter stretching as far back as 2012. In a post on discussion forum Whirlpool, one man said he "never had anything to do" with AAMI before getting what appeared to be a bill for a new green slip. "Without even asking me if I want to renew with them or even checking if I have a CTP green slip with another company, they send me ... simply a bill due 8 Jan," the man wrote. "Seem dodgy to anyone else, or is this just what AAMI do?

"With the words Amount Due and Date Due on it and a payment slip at the bottom, looks awfully like a bill to me." with Lucy Cormack