Many tests that check the quality of biological data are informal, adhoc and under-applied and therefore can miss errors The TDWG Data Quality Interest Group has constructed a suite of tests and assertions that can be applied to a single record or a set of records. Examples are invalid or incomplete dates, geospatial outliers or bad coordinates, suspect depths or elevations, unknown or missing taxa values. Work will continue on implementing selected tests or in some cases, formalise the tests that OBISAU already does to validate data before publication.