PurposeOmnichannel implementation in retail requires business transformation and faces several operational barriers. This research discusses how omnichannel has been implemented, in a managerial perspective, and how integration of operations has overcome the identified transformative barriers.Design/methodology/approachThe authors followed a multi-case study approach, with observation and interviews with managers of four big retail companies in Portugal.FindingsThe results suggest that retail companies have overcome the barriers to implement omnichannel models through the integration of information technology (IT), the accomplishment of organisational changes and the optimisation of customer feedback, achieving positive business indicators, namely increased sales.Research limitations/implicationsThe conclusions of the paper provide valuable information to help companies to design the process of channel's integration in order to overcome the transformative constraints of omnichannel. However, those conclusions emerge from Portuguese case studies of retail companies, and a generalised discussion should consider the contextual diversity of consumer expectations, cultural user experiences in retail and the maturity of digital transformation and omnichannel implementation stage in each country.Originality/valuePrevious studies had characterised the items of omnichannel retail, fulfilment processes, the benefits of channels' integration in customer experience, satisfaction and loyalty and had identified barriers for its implementation. Considering the existence of different stages of omnichannel implementation, this paper explores how retail companies increment omnichannel operations, overcome transformative barriers and achieve the omnichannel benefits, through the whole involvement of the organisation system, the customer approach and the business model, besides the technology integration.