As per a report shared by the Word Bank, GST is having the second highest tax rate in the world. This is the most complex tax structure among 115 countries having a similar sort of indirect tax structure.
There are several exempted sales in GST structure and also few exports are rated to zero tax, which allows exporters to claim refund for taxes paid on inputs. GST is the plan for having one tax across the country instead of having two tax structures; state tax and central tax. Several duties like alcohol, stamp duties on real estate, petroleum products, and electricity are excluded from it. On all these, only state governments can have state specific tax structure. On the other hand, precious stones are now having 0.25% tax and gold has been taxed at the rate of three percent.
The current government had implemented the Goods and Service Tax from 1 July 2017. This tax structure is having five tax slabs of 0, 5%, 12%, 18%, and 28%. The World Bank reported it as the most complex tax system. Around the globe, 49 countries are having a single slab of GST while 28 are having two slabs and only 5 countries including India hold four non-zero slabs. Around the world, countries like Pakistan, Ghana, Italy and Luxembourg use four or more slabs of GST. However, India has the highest number of GST slabs.
However, Finance minister Arun Jaitley has shared that he will be merging 12% and 18% slabs as soon as tax compliance rate improves across the country. This will be done by the government once the revenue buoyancy is increased up to the desired numbers. In November 2017 meeting of the GST Council held in Guwahati, the governing body had also pruned several items under the 28 percent tax slab. Earlier there were 228 items. Now, there are only 50 items in this 28% slab.
In the bi-annual India Development Update released by the World Bank stated that GST was introduced with some sorts of disruptions experienced by state administrations. It was of course, for some initial days only. But, it was indicating a lack of clarity among them as many were confused about discontinuation of state level taxes.
In Tamil Nadu, the state government was having entertainment tax over and above 28% slab of GST. Also, the government of Maharashtra had increased motor vehicle tax to compensate for occurred losses due to introduction of GST.  
The World Bank report has also shown concern over increased administrative tax compliance burden on businesses. Thus, there was an intentional working capital lock in initial days of implementation of this new tax structure in India. And, this report also said that this was happening because of slow tax refund processing. The World Bank further stated that high compliance costs are also arising because the prevalence of multiple tax rates implies a need to classify inputs and outputs based on the applicable tax rate. Along with the need to apply the correct rate, firms are required to match invoices between their outputs and inputs to be eligible for full input tax credit, which increases compliance costs further.
However, the World Bank said while international experience suggests that the adjustment process can affect economic activity for multiple months, the benefits of the GST are likely to outweigh its costs in the long run.
Above all, the World Bank has shown confidence in the success of this idea of new tax structure in India. It has also stated that the benefits of the GST will outweigh its cost in coming future. It has been seen in many countries that such adjustment process may affect the economic process for several months. However, a single key to success is a good policy design. Its success will be possible by adopting minimum compliance burden strategy, simple laws, resourced administration and a balanced mix of education as well as assistance programs.
The World Bank has also advocated for communication campaigns to convey all sorts of beneficial aspects of this new tax system of GST. Indian government should go among businesses, consumers and tax practitioners to pass the real message in an easier language.