Green cards should be given to people driving across the border to confirm they have valid motor insurance in both jurisdictions if a no-deal Brexit hits Ireland.
The Motor Insurers Bureau of Ireland said the industry was prepared to issue cards should a hard border return between the Republic and Northern Ireland.
This week Transport Minister Shane Ross could not say if Brexit will affect existing motor rules.
However, the MIBI's chief executive David Fitzgerald said yesterday options - including potential "green cards" for drivers - need to be considered to resolve the crisis.
"This is to help members of the public who bring their motor vehicles to Northern Ireland or the rest of the UK to be prepared should a ‘no deal’ Brexit occur. The green card is necessary to provide proof of insurance cover," Mr Fitzgerald said.
He said the motor insurance industry has been "preparing for this possibility for months", and that "by the end of this week over 400,000 green card forms" have already been drawn up.
“If there are no further developments and a hard Brexit is still a possibility, then insurance companies and insurance brokers will begin issuing green cards to affected policyholders in March.
"At that point anyone who is planning on driving their motor vehicle in Northern Ireland or elsewhere in the UK is advised to contact their insurer or broker one month in advance of their expected travel date," he said.