There is growing interest and investment in Electronic Immunization Registries (EIRs) with the increasing digitalization of health systems worldwide. The Zindagi Mehfooz (Safe Life) Electronic Immunization Registry (ZMEIR) in Sindh Province, Pakistan is a comprehensive suite of digital health interventions which aims to improve equitable access, timeliness, and coverage of child immunizations through a smartphone-based application (app) for vaccinators, web-based dashboards for supervisors and managers, and a text message reminder system and call centre for caregivers. It is a registry that enrols women and all new-borns or never vaccinated children with a unique ID/QR code assigned to each woman and child. Although originally implemented as an EIR, over the years ZM has evolved as a suite of digital health interventions that goes beyond an EIR when assessed against standard features of EIRs as documented by PATH (2021) and PAHO (2017). In 2012-13, only about half (58.3%) of children (12-23 months) received all basic vaccinations (PDHS 2012-13) in Pakistan, with marked geographic variation across the country; Sindh province had a full immunization coverage of 35% (MICs, 2014). This report documents the impact of ZMEIR on increasing the proportion of children 12-23 months fully immunized in Sindh province through the increased availability and use of data and provides further evidence on the impact and cost-effectiveness of ZM-EIR, which serves to increase the knowledge of the benefits of EIRs as part of a suite of digital health interventions, further contributing to the evidence base related to digital health. ZM-EIR aims to strengthen the EPI service delivery and health system through addressing the problem of low and delayed coverage that leaves children susceptible to vaccine-preventable diseases.