diff --git a/app/controllers/address_search_controller.rb b/app/controllers/address_search_controller.rb
index 74cda65c2..f1d834a11 100644
--- a/app/controllers/address_search_controller.rb
+++ b/app/controllers/address_search_controller.rb
@@ -18,8 +18,8 @@ class AddressSearchController < ApplicationController
         presenter = UprnDataPresenter.new(service.result)
         render json: [{ text: presenter.address, value: presenter.uprn }]
       end
-    elsif query.match?(/[a-zA-Z]/)
-      # Query contains letters, assume it's an address
+    elsif query.match?(/\D/)
+      # Query contains any non-digit characters, assume it's an address
       service = AddressClient.new(query, { minmatch: 0.2 })
       service.call