diff --git a/src/auto-reply/reply/commands-acp/context.test.ts b/src/auto-reply/reply/commands-acp/context.test.ts
index 7fc9093b0ad..ad591588b30 100644
--- a/src/auto-reply/reply/commands-acp/context.test.ts
+++ b/src/auto-reply/reply/commands-acp/context.test.ts
@@ -1,4 +1,4 @@
-import { beforeEach, describe, expect, it } from "vitest";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import type { OpenClawConfig } from "../../../config/config.js";
 import {
   __testing as sessionBindingTesting,
@@ -425,6 +425,10 @@ describe("commands-acp context", () => {
     sessionBindingTesting.resetSessionBindingAdaptersForTests();
   });
 
+  afterEach(() => {
+    setMinimalAcpContextRegistryForTests();
+  });
+
   it("resolves channel/account/thread context from originating fields", () => {
     const params = buildCommandTestParams("/acp sessions", baseCfg, {
       Provider: "discord",
@@ -501,6 +505,58 @@ describe("commands-acp context", () => {
     expect(resolveAcpCommandConversationId(params)).toBe("123456789");
   });
 
+  it("uses the plugin default account when ACP context omits AccountId", () => {
+    setActivePluginRegistry(
+      createTestRegistry([
+        {
+          pluginId: "line",
+          source: "test",
+          plugin: {
+            ...createChannelTestPluginBase({
+              id: "line",
+              label: "LINE",
+              config: {
+                listAccountIds: () => ["default", "work"],
+                defaultAccountId: () => "work",
+              },
+            }),
+            bindings: {
+              resolveCommandConversation: ({
+                originatingTo,
+                commandTo,
+                fallbackTo,
+              }: {
+                originatingTo?: string;
+                commandTo?: string;
+                fallbackTo?: string;
+              }) => {
+                const conversationId =
+                  parseLineConversationIdFromTargetForTest(originatingTo) ??
+                  parseLineConversationIdFromTargetForTest(commandTo) ??
+                  parseLineConversationIdFromTargetForTest(fallbackTo);
+                return conversationId ? { conversationId } : null;
+              },
+            },
+          },
+        },
+      ]),
+    );
+
+    const params = buildCommandTestParams("/acp status", baseCfg, {
+      Provider: "line",
+      Surface: "line",
+      OriginatingChannel: "line",
+      OriginatingTo: "line:user:U1234567890abcdef1234567890abcdef",
+    });
+
+    expect(resolveAcpCommandBindingContext(params)).toEqual({
+      channel: "line",
+      accountId: "work",
+      threadId: undefined,
+      conversationId: "U1234567890abcdef1234567890abcdef",
+    });
+  });
+
   it("builds canonical telegram topic conversation ids from originating chat + thread", () => {
     const params = buildCommandTestParams("/acp status", baseCfg, {
       Provider: "telegram",
diff --git a/src/auto-reply/reply/commands-acp/context.ts b/src/auto-reply/reply/commands-acp/context.ts
index e1cdb5de7f5..c1a1b2af843 100644
--- a/src/auto-reply/reply/commands-acp/context.ts
+++ b/src/auto-reply/reply/commands-acp/context.ts
@@ -13,7 +13,11 @@ export function resolveAcpCommandChannel(params: HandleCommandsParams): string {
 }
 
 export function resolveAcpCommandAccountId(params: HandleCommandsParams): string {
-  return resolveConversationBindingAccountIdFromMessage(params.ctx);
+  return resolveConversationBindingAccountIdFromMessage({
+    ctx: params.ctx,
+    cfg: params.cfg,
+    commandChannel: params.command.channel,
+  });
 }
 
 export function resolveAcpCommandThreadId(params: HandleCommandsParams): string | undefined {
diff --git a/src/auto-reply/reply/conversation-binding-input.ts b/src/auto-reply/reply/conversation-binding-input.ts
index f438f9281d1..1af631c0907 100644
--- a/src/auto-reply/reply/conversation-binding-input.ts
+++ b/src/auto-reply/reply/conversation-binding-input.ts
@@ -1,6 +1,7 @@
 import { normalizeConversationText } from "../../acp/conversation-id.js";
 import { resolveConversationBindingContext } from "../../channels/conversation-binding-context.js";
 import type { OpenClawConfig } from "../../config/config.js";
+import { getActivePluginChannelRegistry } from "../../plugins/runtime.js";
 import type { MsgContext } from "../templating.js";
 import type { HandleCommandsParams } from "./commands-types.js";
 
@@ -27,9 +28,21 @@ function resolveBindingChannel(ctx: BindingMsgContext, commandChannel?: string |
   return normalizeConversationText(raw).toLowerCase();
 }
 
-function resolveBindingAccountId(ctx: BindingMsgContext): string {
-  const accountId = normalizeConversationText(ctx.AccountId);
-  return accountId || "default";
+function resolveBindingAccountId(params: {
+  ctx: BindingMsgContext;
+  cfg: OpenClawConfig;
+  commandChannel?: string | null;
+}): string {
+  const channel = resolveBindingChannel(params.ctx, params.commandChannel);
+  const plugin = getActivePluginChannelRegistry()?.channels.find(
+    (entry) => entry.plugin.id === channel,
+  )?.plugin;
+  const accountId = normalizeConversationText(params.ctx.AccountId);
+  return (
+    accountId ||
+    normalizeConversationText(plugin?.config.defaultAccountId?.(params.cfg)) ||
+    "default"
+  );
 }
 
 function resolveBindingThreadId(threadId: string | number | null | undefined): string | undefined {
@@ -45,10 +58,15 @@ export function resolveConversationBindingContextFromMessage(params: {
   parentSessionKey?: string | null;
   commandTo?: string | null;
 }): ReturnType<typeof resolveConversationBindingContext> {
+  const channel = resolveBindingChannel(params.ctx);
   return resolveConversationBindingContext({
     cfg: params.cfg,
-    channel: resolveBindingChannel(params.ctx),
-    accountId: resolveBindingAccountId(params.ctx),
+    channel,
+    accountId: resolveBindingAccountId({
+      ctx: params.ctx,
+      cfg: params.cfg,
+      commandChannel: channel,
+    }),
     chatType: params.ctx.ChatType,
     threadId: resolveBindingThreadId(params.ctx.MessageThreadId),
     threadParentId: params.ctx.ThreadParentId,
@@ -83,8 +101,12 @@ export function resolveConversationBindingChannelFromMessage(
   return resolveBindingChannel(ctx, commandChannel);
 }
 
-export function resolveConversationBindingAccountIdFromMessage(ctx: BindingMsgContext): string {
-  return resolveBindingAccountId(ctx);
+export function resolveConversationBindingAccountIdFromMessage(params: {
+  ctx: BindingMsgContext;
+  cfg: OpenClawConfig;
+  commandChannel?: string | null;
+}): string {
+  return resolveBindingAccountId(params);
 }
 
 export function resolveConversationBindingThreadIdFromMessage(
diff --git a/src/channels/conversation-binding-context.test.ts b/src/channels/conversation-binding-context.test.ts
new file mode 100644
index 00000000000..f5297b28cae
--- /dev/null
+++ b/src/channels/conversation-binding-context.test.ts
@@ -0,0 +1,61 @@
+import { afterEach, describe, expect, it } from "vitest";
+import type { OpenClawConfig } from "../config/config.js";
+import { setActivePluginRegistry } from "../plugins/runtime.js";
+import { createChannelTestPluginBase, createTestRegistry } from "../test-utils/channel-plugins.js";
+import { resolveConversationBindingContext } from "./conversation-binding-context.js";
+
+describe("resolveConversationBindingContext", () => {
+  afterEach(() => {
+    setActivePluginRegistry(createTestRegistry());
+  });
+
+  it("uses the plugin default account when accountId is omitted", () => {
+    setActivePluginRegistry(
+      createTestRegistry([
+        {
+          pluginId: "line",
+          source: "test",
+          plugin: {
+            ...createChannelTestPluginBase({
+              id: "line",
+              label: "LINE",
+              config: {
+                listAccountIds: () => ["default", "work"],
+                defaultAccountId: () => "work",
+              },
+            }),
+            bindings: {
+              resolveCommandConversation: ({
+                originatingTo,
+                commandTo,
+                fallbackTo,
+              }: {
+                originatingTo?: string;
+                commandTo?: string;
+                fallbackTo?: string;
+              }) => {
+                const conversationId = [originatingTo, commandTo, fallbackTo]
+                  .map((candidate) => candidate?.trim().replace(/^line:/i, ""))
+                  .map((candidate) => candidate?.replace(/^user:/i, ""))
+                  .find((candidate) => candidate && candidate.length > 0);
+                return conversationId ? { conversationId } : null;
+              },
+            },
+          },
+        },
+      ]),
+    );
+
+    expect(
+      resolveConversationBindingContext({
+        cfg: {} as OpenClawConfig,
+        channel: "line",
+        originatingTo: "line:user:U1234567890abcdef1234567890abcdef",
+      }),
+    ).toEqual({
+      channel: "line",
+      accountId: "work",
+      conversationId: "U1234567890abcdef1234567890abcdef",
+    });
+  });
+});
diff --git a/src/channels/conversation-binding-context.ts b/src/channels/conversation-binding-context.ts
index 8f7d5df2cad..7eb74caca7c 100644
--- a/src/channels/conversation-binding-context.ts
+++ b/src/channels/conversation-binding-context.ts
@@ -59,6 +59,18 @@ function shouldDefaultParentConversationToSelf(plugin?: ChannelPlugin): boolean
   return plugin?.bindings?.selfParentConversationByDefault === true;
 }
 
+function resolveBindingAccountId(params: {
+  rawAccountId?: string | null;
+  plugin?: ChannelPlugin;
+  cfg: OpenClawConfig;
+}): string {
+  return (
+    normalizeText(params.rawAccountId) ||
+    normalizeText(params.plugin?.config.defaultAccountId?.(params.cfg)) ||
+    "default"
+  );
+}
+
 function resolveChannelTargetId(params: {
   channel: string;
   target?: string | null;
@@ -124,9 +136,13 @@ export function resolveConversationBindingContext(
   if (!channel) {
     return null;
   }
-  const accountId = normalizeText(params.accountId) || "default";
-  const threadId = normalizeText(params.threadId != null ? String(params.threadId) : undefined);
   const loadedPlugin = getLoadedChannelPlugin(channel);
+  const accountId = resolveBindingAccountId({
+    rawAccountId: params.accountId,
+    plugin: loadedPlugin,
+    cfg: params.cfg,
+  });
+  const threadId = normalizeText(params.threadId != null ? String(params.threadId) : undefined);
 
   const resolvedByProvider = loadedPlugin?.bindings?.resolveCommandConversation?.({
     accountId,