diff --git a/public/css/style.css b/public/css/style.css
index c920b5c..ce048ad 100644
--- a/public/css/style.css
+++ b/public/css/style.css
@@ -174,6 +174,9 @@ button:disabled { opacity: 0.45; cursor: not-allowed; }
 
 .btn-ghost { background: transparent; color: var(--text-muted); }
 .btn-ghost:hover { color: var(--text); background: var(--bg); }
+.btn-danger { background: #dc2626; color: #fff; font-weight: 500; }
+.btn-danger:not(:disabled):hover { background: #b91c1c; }
+.delete-account-row { margin-bottom: 18px; padding-bottom: 16px; border-bottom: 1px solid var(--border); }
 
 .btn-icon {
   background: transparent;
diff --git a/public/index.html b/public/index.html
index 2e8c028..7d6bd99 100644
--- a/public/index.html
+++ b/public/index.html
@@ -300,6 +300,10 @@
     <div class="modal-body">
       <form id="acct-settings-form" novalidate>
 
+        <div class="delete-account-row">
+          <button type="button" id="btn-delete-account" class="btn-danger">Delete Account</button>
+        </div>
+
         <p class="settings-section-label">Organization</p>
         <div class="form-group required">
           <label for="as-company1">Name</label>
@@ -413,6 +417,25 @@
     </div>
   </div>
 
+  <!-- Delete account confirmation modal -->
+  <div id="delete-account-overlay" class="modal-overlay"></div>
+  <div id="delete-account-modal" class="modal" role="dialog" aria-labelledby="delete-account-title">
+    <div class="modal-header">
+      <h2 id="delete-account-title">Delete Account</h2>
+      <button id="btn-close-delete-account" class="btn-icon" title="Close">×</button>
+    </div>
+    <div class="modal-body">
+      <div class="warning-box" style="background:#fef2f2;border-color:#f87171;color:#7f1d1d">
+        <strong>This cannot be undone.</strong> Deleting this account will permanently remove all checks, deposits, and account settings. There is no recovery.
+      </div>
+      <p style="margin-top:14px;font-size:13px">Are you sure you want to delete <strong id="delete-account-name"></strong>?</p>
+    </div>
+    <div class="modal-footer">
+      <button id="btn-confirm-delete-account" class="btn-danger">Yes, Delete Account</button>
+      <button id="btn-cancel-delete-account" class="btn-ghost">Cancel</button>
+    </div>
+  </div>
+
   <!-- QBO Import modal -->
   <div id="qbo-import-overlay" class="modal-overlay"></div>
   <div id="qbo-import-modal" class="modal modal-wide" role="dialog" aria-labelledby="qbo-import-title">
diff --git a/public/js/app.js b/public/js/app.js
index 60c2946..34fcd5c 100644
--- a/public/js/app.js
+++ b/public/js/app.js
@@ -644,6 +644,40 @@ async function saveAccountSettings() {
   }
 }
 
+// ── Delete account ────────────────────────────────────────────────────────────
+
+function openDeleteAccount() {
+  const name = (state.account && state.account.company1) || 'this account';
+  document.getElementById('delete-account-name').textContent = name;
+  document.getElementById('delete-account-overlay').classList.add('open');
+  document.getElementById('delete-account-modal').classList.add('open');
+}
+
+function closeDeleteAccount() {
+  document.getElementById('delete-account-overlay').classList.remove('open');
+  document.getElementById('delete-account-modal').classList.remove('open');
+}
+
+async function confirmDeleteAccount() {
+  const btn = document.getElementById('btn-confirm-delete-account');
+  btn.disabled = true;
+  btn.textContent = 'Deleting…';
+  try {
+    await apiFetch('DELETE', `/api/account/${state.activeAccountId}`);
+    closeDeleteAccount();
+    closeAccountSettings();
+    state.account = null;
+    state.activeAccountId = null;
+    state.checks = [];
+    localStorage.removeItem('activeAccountId');
+    await loadAccounts(); // will open wizard if no accounts remain
+  } catch (err) {
+    alert('Delete failed: ' + err.message);
+    btn.disabled = false;
+    btn.textContent = 'Yes, Delete Account';
+  }
+}
+
 // ── QBO Import ────────────────────────────────────────────────────────────────
 
 let qboChecksRecords = null;
@@ -1241,6 +1275,12 @@ function init() {
   document.getElementById('acct-settings-overlay').addEventListener('click', closeAccountSettings);
   document.getElementById('btn-save-acct-settings').addEventListener('click', saveAccountSettings);
 
+  document.getElementById('btn-delete-account').addEventListener('click', openDeleteAccount);
+  document.getElementById('btn-close-delete-account').addEventListener('click', closeDeleteAccount);
+  document.getElementById('btn-cancel-delete-account').addEventListener('click', closeDeleteAccount);
+  document.getElementById('delete-account-overlay').addEventListener('click', closeDeleteAccount);
+  document.getElementById('btn-confirm-delete-account').addEventListener('click', confirmDeleteAccount);
+
   document.getElementById('btn-set-check-no').addEventListener('click', openSetCheckNo);
   document.getElementById('btn-close-set-check-no').addEventListener('click', closeSetCheckNo);
   document.getElementById('btn-cancel-set-check-no').addEventListener('click', closeSetCheckNo);
diff --git a/src/app.js b/src/app.js
index 5f7f107..c4369ab 100644
--- a/src/app.js
+++ b/src/app.js
@@ -104,6 +104,22 @@ app.put('/api/account/:id/check-no', (req, res) => {
   res.json({ next_check_no: next });
 });
 
+// DELETE /api/account/:id - delete account and all associated data
+app.delete('/api/account/:id', (req, res) => {
+  const db = require('./db/database');
+  const account = db.prepare('SELECT id FROM account WHERE id = ?').get(req.params.id);
+  if (!account) return res.status(404).json({ error: 'Account not found.' });
+
+  db.transaction(() => {
+    // deposit_items deleted via ON DELETE CASCADE from deposits
+    db.prepare('DELETE FROM deposits WHERE account_id = ?').run(req.params.id);
+    db.prepare('DELETE FROM checks WHERE account_id = ?').run(req.params.id);
+    db.prepare('DELETE FROM account WHERE id = ?').run(req.params.id);
+  })();
+
+  res.status(204).end();
+});
+
 // POST /api/account/setup - create a new account (wizard)
 app.post('/api/account/setup', (req, res) => {
   const db = require('./db/database');