diff --git a/apps/scandic-web/utils/refId.ts b/apps/scandic-web/utils/refId.ts
index 95a0aef05..e594b9fd9 100644
--- a/apps/scandic-web/utils/refId.ts
+++ b/apps/scandic-web/utils/refId.ts
@@ -9,7 +9,12 @@ export function calculateRefId(confirmationNumber: string, lastName: string) {
 }
 
 export function parseRefId(refId: string) {
-  const data = decrypt(refId)
+  // Some external systems that link to us do not encode the refId parameter
+  // properly, so we reverse the decoding of plus sign into spaces.
+  // Slash and equal sign are not decoded into anything, so no action needed.
+  // We only need to cater for those three (plus, slash, equals) as RefId is
+  // Base64 encoded which only has these three special characters.
+  const data = decrypt(refId.replace(/ /g, "+"))
   const parts = data.split(",")
   if (parts.length !== 2) {
     throw new Error("Invalid refId format")