In January 2015 the MHRA released a guidance document on Good Manufacturing Practice (GMP) data integrity. An update to this guidance was released this month to include additional clarifications following questions from industry. The guidance sets out expectations for data integrity in GMP and complements existing EU GMP relating to active substance and dosage forms, and should be read in conjunction with national medicines legislation and the GMP standards published in Eudralex volume 4 . Data integrity requirements apply equally to paper and electronic data. The guidance provides definitions of terms such as ‘raw data’, ‘metadata’, data lifecycle’, ‘audit trail’ and the expectations/guidance associated with each. It gives examples of the varying complexity of systems which may generate data and the inherent risks to data integrity posed by these systems. Although this guidance has been released in relation to GMP, it is worthy of note across the different GxPs.