Delay In Security For Costs Applications

When a defendant has grounds to seek security for costs, how long can it wait before making the application?

The Supreme Court (Court) considered delay in security for costs applications in Sweeney & Anor v The Voluntary Health Insurance Board [2026] IESC 32. The Court noted that the starting point is that the application should be made “as soon as reasonably possible” once the grounds for bringing it are known or could with due diligence have become known. What is reasonable will be fact-dependent, but usually this means “weeks or possibly months” rather than years.

In Sweeney, almost eight years passed between VHI raising security for costs and issuing its application. The Supreme Court described that delay as “truly extraordinary” and held that it was sufficient to justify refusing security. The judgment also addresses when the clock starts running, how delay interacts with prejudice, and, importantly, when delay may itself be sufficient to defeat an otherwise valid application.