Atol Certificates come into force today, with the government hailing the new documents as a source of clarity but Abta warning of confusion.
Agents and tour operators are legally required to issue Atol Certificates to consumers buying protected holidays on receipt of any payment.
Aviation minister Simon Burns said: "The Atol Certificate will give peace of mind to millions.
"I want this certificate to become a standard travel document that families will expect alongside their flight tickets and holiday details."
Dame Deirdre Hutton, chair of the Civil Aviation Authority (CAA), said: "Consumers have told us they want more clarity about how their holidays are protected.
"The Atol Certificate will mean people can clearly see on one standard document what is protected, who is protecting it and what they should do if their holiday company fails."
She added: "It's a change that will make simple what currently can seem very complex. With the certificate consumers have protection, without it they do not."
Hutton confirmed last week that there will be a short "grace period" for travel companies to complete the process of compliance.
She said: "We will continue to help people, but in the end we will enforce the law."
Abta has launched a checklist for consumers with advice on what paperwork to look for when booking a holiday.
Association chief executive Mark Tanzer welcomed the launch but warned that confusion would remain.
Tanzer said: "Atol Certificates are only evidence of Atol protected holidays. There is still much confusion about what holiday arrangements are or are not protected by Atol.
"Abta estimates that about 50% of holiday arrangements sit outside the Atol scheme."
He said Abta's Protection Checklist would help holidaymakers understand what to look for.