By July 2018, five countries (Australia, France, the UK, New Zealand and Norway) had fully implemented plain (standardised) packaging. Using government documents, we reviewed the key legislative differences between these five countries to identify best practice measures and potential lacuna. We then discuss how governments planning to introduce plain packaging could strengthen their legislation. Differences between countries include the terminology used (either ‘plain’, ‘standardised’ or ‘plain and standardised’), products covered and transition times (ranging from 2 to 12 months). Myriad differences exist with respect to the packaging, including the dimensions (explicitly stated for height, width and depth vs minimum dimensions for the health warnings only), structure (straight-edged flip-top packs vs straight, rounded and bevelled-edged flip-top packs and shoulder boxes) and size (minimum number of cigarettes and weight of tobacco vs fixed amounts) and warning content (eg, inclusion of a stop-smoking web address and/or quitline displayed on warnings on one or both principal display areas). Future options that merit further analysis include banning colour descriptors in brand and variant names, allowing pack inserts promoting cessation and permitting cigarettes that are designed to be dissuasive. Plain packaging legislation and regulations are divergent. Countries moving towards plain packaging should consider incorporating the strengths of existing policies and review opportunities for extending these. While plain packaging represents a milestone in tobacco-control policy, future legislation need not simply reflect the past but could set new benchmarks to maximise the potential benefits of this policy.