The threshold for registration in the system of value added tax (VAT) resulting exemption from payment of VAT for companies with an annual turnover of goods and services below the prescribed level. Determining the optimal threshold for registration involves balancing (trade-off) costs and benefits to taxpayers and tax authority To minimize negative and maximize the positive implications of the existence threshold at the microeconomic, macroeconomic and fiscal system. The threshold for registration represents a lever fiscal personaliza-tion to ensure the privileged situation of small firms in the VAT system. Analysis of the practices of developed countries and the factors that determine the threshold level for registration is shown that, under conditions of high heterogeneity of small taxpayers, policy of high threshold with the option of voluntary registration for VAT for smal companies represents a desirable design elements of VAT system in each country.