The final package of measures proposed by the OECD as part of its base erosion and profit shifting (Beps) project will be presented to G20 leaders in Turkey this weekend.

The new Beps rules are designed to improve transparency, close loopholes and restrict the use of tax havens. Companies such as Starbucks, Amazon and Google will find it harder to concentrate their profits in low-tax countries and tax havens, a shift that promises to raise up to $250 billion a year in extra tax revenue, according to the OECD .

The Beps rules are the culmination of an international project launched two years ago by G20 governments in response to public anger over corporate tax avoidance.

Almost 90 countries worldwide have been working together to come up with a multilateral instrument that can integrate the Beps measures into the bilateral treaties already in place.

Following delivery of the Beps measures to G20 leaders during their annual summit in Antalya this weekend, the focus will shift to designing and putting in place an inclusive framework for monitoring Beps and supporting implementation of the measures, with all interested countries and jurisdictions invited to participate on an equal footing.

The final package of Beps measures includes new minimum standards on country- by-country reporting, which for the first time will give tax administrations a global picture of the operations of multinational enterprises.

The comprehensive set of reforms, aimed at changing international tax rules, won strong support for its proposed solutions to close loopholes that allow corporate profits to “disappear” for tax reasons.