diff --git a/sidepanel/sidepanel.html b/sidepanel/sidepanel.html
index 1a92415..3d93895 100644
--- a/sidepanel/sidepanel.html
+++ b/sidepanel/sidepanel.html
@@ -361,7 +361,7 @@
       <div class="data-row" id="row-hosted-checkout-phone" style="display:none;">
         <span class="data-label">直绑电话</span>
         <input type="text" id="input-hosted-checkout-phone" class="data-input"
-          placeholder="PayPal guest checkout 使用的电话" autocomplete="tel" />
+          placeholder="填 10 位美国本地号码，不要带 +1" autocomplete="tel" />
       </div>
       <div class="data-row" id="row-plus-hosted-checkout-oauth-delay" style="display:none;">
         <span class="data-label">成功等待</span>