The hallmarking of gold jewellery will become mandatory at one go across the nation from January 15, 2020, and will not be implemented in phases, as was expected earlier. However, the Centre has given a year's time to comply with the new norm, which means that while the notification will be issued by January 15 next year, jewellers will be given time until January 2021, after which they will only be allowed to sell hallmarked ornaments.