From the time when the highest personal income tax rates in the country were as crippling as 97% to 34.6% today, India has come a long way in rationalising its tax structures, and Wednesday\u2019s ratification of the Constitutional Amendment Bill for GST is possibly the culmination of a long journey that began in 1991\u2014and, as in the case of GST which was originally kicked off by the UPA in 2006, the reforms have been pushed forward by all parties. Customs duties have fallen from their peak of 150% in 1991-92% to as low as 10% today; there are a handful of excise duty rates today centred around a median rate as opposed to the plethora earlier. India moved towards tax credits several years ago, which the GST will extend even further and, given the tremendous value-creation in the services sector that was hardly captured, a service tax was also introduced in 1993\u2014today, service taxes account for 14.2% of all central tax collections and, more important, socially progressive direct tax collections overtook indirect tax collections way back in FY08. As in any such journey, there is a long list of those who made such reforms possible, starting from then finance minister Manmohan Singh. The initial reforms on direct taxes were carried out based on the prescription laid out by the late Raja Chelliah whose mantra was the evolution of a tax system focused on broadening the base and levying lower and less differentiated rates\u2014based on a report written by M Govinda Rao, Chelliah recommended the introduction of service taxation; replacing state sales taxes with VAT was also a Chelliah recommendation. Then finance minister Yashwant Sinha took the big steps in simplifying excise duty rates and coming to a moderate central rate. While it was P Chidambaram that first proposed the GST in 2006\u2014it was to become operational on April 1, 2010\u2014a large part of the credit to ensuring the states came on board, and their concerns addressed, has to belong to the heads of the empowered committee on state finance ministers like Asim Dasgupta, Sushil Modi and Amit Mitra. While the BJP played the spoiler at that time, BJP states like Gujarat almost scuttled it this time around as well\u2014chief economic advisor Arvind Subramanian played a stellar intellectual role in highlighting how this would hurt Make-in-India and, to their credit, both prime minister Narendra Modi and finance minister Arun Jaitley went by his advice. Through all of this, the biggest problem was that India\u2019s tax collections didn\u2019t rise in keeping with the increased efforts at tax simplifications. At the central level, the tax-to-GDP ratio was 9.8% in 1990-91, rose to 11.9% in FY08 and is 10.6% today\u2014at the level of the states, the ratio rose from 5.2% in 1990-91 to 6.9%in FY16. Several amnesty schemes over the past decades haven\u2019t helped much, nor have various other schemes which gave the taxman more information about spending habits of citizens. Given how a fully computerised tax information network is an integral part of the GST, once the GST Network is put in place, it will play a big role in increasing tax compliance since most transactions will get captured at some point or the other in the value-chain; the fact that real estate has been kept out of the purview of GST is a spoiler, apart from the fact that this will also lead to large amounts of un-rebated tax credits. Apart from the fact that GST makes a fundamental shift from an origin-based tax to a destination-based one, its biggest contribution will lie in eliminating the border check-posts that dot all state boundaries\u2014it is these check-posts that ensure India is not a single-market which, in turn, ensures that trucks line up at border posts for hours while their cargo and manifests are subject to laborious checks. Much of the increased GDP growth that economists estimate will accrue emanate from this reduction in transportation costs\u2014to the extent that a GST means companies will no longer plan their warehouses based on tax rates in different states, logistics costs will also get rationalised. State governments, it is true, have yet to agree to eliminate the border posts, but once all information via invoices are uploaded to the GSTN and states find their tax collections are rising, chances are check-posts will get eliminated over a period of time \u2014 if they don\u2019t, a big potential GST benefit will no longer accrue, making the exercise a less useful one. As in any ambitious tax proposal, there are serious flaws that need fixing, and governments have several months to fix this. Asking firms to ensure that everyone before them in the value-chain has paid taxes before they get input tax credits is inexplicable and draconian, and the discretionary valuation of goods and services can cause serious problems\u2014it is not clear why, as in the rest of the world, invoice-based valuation is not acceptable with well-defined ways to deal with discounts offered on final sales. Valuing intra-firm supplies is another huge problem area and, here too, there are well-accepted global procedures. With a well-functioning GSTN, similarly, it is not clear why firms have to register with each state\/UT and pay taxes at that level. Rules on e-commerce, similarly, are very complex. The biggest issue, of lower rates, remains unaddressed \u2014 this requires slashing exemptions \u2014 and that is critical if the benefits of lower taxation, including higher compliance, are to accrue to the economy. Till then, it\u2019s too early to celebrate.