Scholarship on labour informalisation in Vietnam pulls in two different directions. One set of policy-focused literature suggests that there is an increasing formalisation of labour. Literature of critical labour studies and cognate disciplines, however, suggests the opposite; an increasing informalisation of labour as workers must accept less security of employment and income. This article argues that these two trends are both true, and that there has been a simultaneous expansion and informalisation of formal labour. It introduces the concept of the informalising-formalising labour regime. The formalising element of the informalising-formalising labour regime means that increasing numbers of people have been brought into the formal economy, as salaried workers with contracts. Concurrently, work within the formal economy has become increasingly informal. Such workers may enjoy some legal benefits or entitlements, but in comparison to previously existing formal urban jobs this work is much less secure. Viewing informalisation as a form of class struggle from above, the article argues that employers in the garment and footwear industry use many techniques to informalise work. It outlines the informalising-formalising labour regime, focusing on various concrete techniques used by capital to fragment working class power.