diff --git a/app/views/facilities_management/buyer_details/edit.html.erb b/app/views/facilities_management/buyer_details/edit.html.erb
index 96297a6141..8077dc9d98 100644
--- a/app/views/facilities_management/buyer_details/edit.html.erb
+++ b/app/views/facilities_management/buyer_details/edit.html.erb
@@ -51,7 +51,7 @@
           label: {
             text: t('.telephone_number')
           },
-          classes: 'govuk-!-width-one-half',
+          classes: 'govuk-!-width-one-half ccs-integer-field',
           attributes: {
             required: true,
             autocomplete: "off"