Case Study: National Savings & Investments achieves major digital engagement gains and £750K+ annual savings with Optimizely

NS&I revamp digital touchpoints with experimentation

National Savings & Investments (NS&I), a UK savings organisation with 25 million customers and £157 billion invested, set out to simplify its online experience and move customers away from paper-based, high-cost channels. Working with Atos and Optimizely, NS&I formed an agile five-person WebOps team to tackle three goals: optimise customer experience, shift engagement to self‑serve digital channels, and reduce cost-to-serve.

Using Optimizely experimentation, the WebOps team ran concurrent tests and rolled out 54 validated website changes in seven months (vs. nine in 2016), shortening delivery from 16 weeks to two-week cycles. Results included a 715% increase in click-throughs to the Premium Bonds prize checker, a 39% rise in customers choosing digital journeys, a 45% increase in help-article helpfulness, a 68% uplift in Premium Bonds top-ups, a 70%+ increase in app-store clicks, savings of over £750,000, and 14 million experiment visits (~£0.07 per insight).

National Savings and Investments