Thousands of Irish businesses should receive €2,000 for dealing with customs for the first time after Brexit, a lobby group said.
An estimated 60,000 small and medium-sized firms which trade with the UK would be eligible for vouchers from the Government if the proposal by the British Irish Chamber of Commerce is adopted.
It would target traders who are ill-equipped for the extra red tape created by customs procedures.
The report said: "The costs associated with training and the on-going administrative burden for small and medium-sized enterprises will be significant."
The Chamber recommended that the voucher scheme would be open to all small or medium-sized companies dealing with customs for the first time to help them seek specialist advice and train staff.
The report added: "These SMEs currently trade with UK exporters and importers as if they were in their home market.
"Many of these SMEs will be ill-equipped for the administrative and logistical burden of dealing with customs procedures on a regular basis."
Smaller firms are by far the most numerous in Ireland.
The British Government has proposed a future customs arrangement which would see 80% of businesses on the island entirely exempt from any new tariffs post-Brexit.
The exemption would apply to small and medium-sized enterprises involved in localised cross-border trade.
UK Government suggestions would see larger companies engaged in international trade adhering to any new customs regime by completing retrospective declarations either online or at their premises.
If the UK exits the single market after March 2018, barriers to trade will include custom controls, rules of origin checks, differences in regulations, diverging standards and anti-dumping duties, the British Irish Chamber said.
85,000 Irish businesses trade with the UK, of which 68,000 are small to medium traders - it is estimated 60,000 of these will be dealing with customs for the first time, the report said.
Revenue calculations suggest that custom declarations in Ireland will go from one million to 20 - 30 million, it added.
According to the OECD, crossing the border, documentation and customs compliance requirements, lengthy administrative procedures and other delays can increase transaction costs by up to a quarter of the value of traded goods.
In some countries, revenue losses from inefficient border procedures may exceed 5% of GDP.