This paper presents indices of regulatory heterogeneity based on the rich information in the STRI regulatory database. The indices are built from assessing – for each country pair and each measure – whether or not the countries have the same regulation. For each country pair and each sector, the indices reflect the (weighted) share of measures for which the two countries have different regulation. Estimates of the relationship between regulatory heterogeneity and trade shows that on average a reduction in the regulatory heterogeneity by 0.05 points is associated with 2.5% higher services exports and that the impact is larger the lower the level of trade restring regulation. The trade costs associated with the average score on the regulatory heterogeneity index (0.26) amounts to an ad valorem equivalent trade cost of between 20 and 75% at low levels of the STRI. Regulation has become slightly more similar from 2014 to 2015 in telecommunications. For the other sectors, countries have become slightly less similar over the same period.