How do the Guatemala–Honduras customs union and Central American economic integration work?

Guatemala ratified the framework for the customs union with Honduras in 2016 and implementation began in 2017; El Salvador opened accession negotiations that same year. SIECA runs the 'Deep Integration: El Salvador, Guatemala and Honduras' platform and the Economic Intelligence Observatory with regional statistics. The general legal framework, the General Treaty on Central American Economic Integration, the Guatemala Protocol and others, is published by MINECO. The operational detail (the exact start date, reported in the press as Jun 26, 2017; the FYDUCA as a single tax document; the share of bilateral trade covered; the integrated peripheral customs posts; El Salvador's formal progress) was not verified with a primary source, so no figures are recorded.