Bulgarian competition authority (CPC) approved a new template of merger notification and guidelines on its contents, effective as from 1 January 2020. At first look it appears that the new guidelines significantly expand the scope of necessary information, including by requiring the parties to provide economic assessments on how the markets functions. Further, CPC introduces the notions of “significantly affected markets”, “a significant horizontal overlapping” (if the combined market share exceed 15 %) and “significantly related markets” (if the market share of each participant on each market is at least 25 %). The merger notification in such cases would require a more detailed and high-profile economic information, including historical data and forecasts, which might be difficult for the parties to produce themselves without the assistance of, at least, economic consultants. While the paper is still under internal analysis and evaluation of its possible implications, in any event the change will make the merger clearance process more onerous than it used to be, will inevitably increase the  time and cost of preparation of the filings and might create additional risks for the companies to be sanctioned for lack of cooperation (by providing incomplete information, or even entail the risk of self-reporting). The template and the guidelines thereto are available in Bulgarian on the following link: http://reg.cpc.bg/Decision.aspx?DecID=300056739