India's Prime Minister Narendra Modi arrives to take part in the G20 Summit in Brisbane on November 15, 2014.Reuters

G20 leaders on Sunday endorsed India's concerns over black money and tax avoidance, and promised to modernise global tax rules and begin automatic exchange of tax information by 2018-end.

The Indian government called the outcome an "unprecedented success."

On the second and final day of the G20 Summit here, Modi reiterated his call for close policy coordination among major economies, saying this was important not just for addressing the challenge of black money, but also to battle terrorism, drug trafficking and arms smuggling.

Addressing a G20 session - Delivering Global Economic Resilience, the prime minister also voiced support for a new global automatic exchange of information, saying it would be instrumental in getting data about the unaccounted money stashed abroad and help bring it back.

In a joint communique issued at the end of the summit, the leaders said: "We welcome the significant progress on the G20/OECD (Organisation of Economic Cooperation and Development) Base Erosion and Profit Shifting (BEPS) Action Plan to modernise international tax rules."

"We are committed to finalising this work in 2015, including transparency of taxpayer-specific rulings found to constitute harmful tax practices."

The communique said that to prevent cross-border tax evasion, "we endorse the global Common Reporting Standard for the automatic exchange of tax information on a reciprocal basis.

"We will begin to exchange information automatically with each other and with other countries by 2017 or end-2018, subject to completing necessary legislative procedures," it stated.

Railway Minister Suresh Prabhu, the Prime Minister's Sherpa or interlocutor for the G20, and external affairs ministry spokesperson Syed Akbaruddin termed the outcome an "unprecedented success".

"We have achieved substantially or overwhelmingly all our goals, in terms of the outcomes of the communique," Akbaruddin told the media.

After the communique was issued, the Prime Minister's Office tweeted: "India's concerns on black money and tax avoidance have found an echo and have been taken on board the final G-20 communique.

It also tweeted about the communique's reference to the BEPS action plan and transparency in taxpayer specific rulings constituting harmful tax practices.

"India scores at G-20," Akbaruddin tweeted.

"PM @narendramodi strong intervention gets backing for inclusion in tax matters in final communique."

The G20, taking into consideration the concerns of India and other developing countries, also vowed to take "strong practical" measures to reduce the global average cost of transferring remittances to five percent.

India, which gets the largest remittances at over $71 billion, had called for a reduction in the remittance costs, which is sometimes at a high of 10 percent.

This apart, leaders of the world's largest developed countries and emerging economies said in the communique that their top priority was raising global growth to deliver better living standards and quality jobs for people across the world.

"Raising global growth to deliver better living standards and quality jobs for people across the world is our highest priority. We welcome stronger growth in some key economies," the communique stated.