diff --git a/typescript/organisations.d.ts b/typescript/organisations.d.ts
index 3e6f7e7..9330e37 100644
--- a/typescript/organisations.d.ts
+++ b/typescript/organisations.d.ts
@@ -37,6 +37,7 @@ export type NewOrganisation = {
   requireTeamMemberMfa?: boolean
   environmentOrdering?: number[]
   formsBuilderAISystemConfigurationIdOverride?: number
+  externalId?: string
 }
 
 export type Organisation = NewOrganisation & {