More than three million Australians who have self-identified as being problem or at-risk gamblers could be vulnerable to a proliferation of text messages sent by betting companies.

While there are strict laws governing gambling ads on TV, radio or online, the rules when it comes to texts are much looser.

So how often can a gambling company send an SMS message, and what are the rules around the practice?

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All direct communication must include a disclaimer

Legally, gambling companies are required to include just two things in direct marketing material like texts: consistent messaging about the risks and potential harm of gambling, and a way for consumers to opt out.

That means all texts must include specific taglines like "chances are you're about to lose'"and a link or instructions to unsubscribe.

Betting companies can also only send direct marketing materials to customers who provide "express consent" to receive it, per the National Consumer Protection Framework for Online Wagering.

Companies that send texts after a consumer has unsubscribed are in breach of the Australian Communications and Media Authority's spam rules

Earlier this year Tabcorp copped a $4 million fine for spamming VIP customers with thousands of messages without any way to unsubscribe.

In 2022, Sportsbet was ordered to pay $3.7 million in fines for sending more than 150,000 texts and emails to about 37,000 customers who had tried to unsubscribe.

Have you got a story? Contact reporter Maddison Leach at how to talk with someone about their gambling; or contact Gamblers Anonymous.

All services are free, confidential and available 24 hours a day, 7 days a week.