diff --git a/plugins/POS.py b/plugins/POS.py
index 42fd8a8..c0243c5 100644
--- a/plugins/POS.py
+++ b/plugins/POS.py
@@ -113,7 +113,7 @@ def projected_balance(self, user):
         checkout_balances = getattr(self.master.accounts, "checkout_balances", {})
         if not isinstance(checkout_balances, dict):
             checkout_balances = {}
-        account = self.master.accounts.accounts[user]
+        account = self.master.accounts.accounts.get(user, {"amount": 0})
         balance_before_checkout = checkout_balances.get(user, account["amount"])
         return balance_before_checkout + self.master.receipt.totals[user]
 
diff --git a/plugins/accounts.py b/plugins/accounts.py
index 76a52b8..3d426e2 100644
--- a/plugins/accounts.py
+++ b/plugins/accounts.py
@@ -132,6 +132,12 @@ def updateaccount(self, usr, value):
         logger.debug("update_account sid=%s user=%s value=%s", self.SID, usr, value)
         if usr == "cash":
             return
+        if usr not in self.accounts:
+            logger.warning("missing_account_created_during_checkout user=%s", usr)
+            self.accounts[usr] = {
+                "amount": 0,
+                "lastupdate": time.strftime("%Y-%m-%d_%H:%M:%S"),
+            }
         had = self.accounts[usr]["amount"]
         self.accounts[usr]["amount"] += value
         has = self.accounts[usr]["amount"]
@@ -179,7 +185,7 @@ def createnew(self, text):
                 "amount": 0,
                 "lastupdate": time.strftime("%Y-%m-%d_%H:%M:%S"),
             }
-            return self.input(self.newaccount)
+            return self._use_account(self.newaccount)
         if text == "no":
             return True
         if text == "abort":
@@ -308,26 +314,41 @@ def askalias(self, text):
             return self.messageandbuttons("addalias", "keyboard", "What alias to add?")
         return None
 
-    # This handles the input
-    def input(self, text):
-        if self.master.receipt.is_empty() and (
-            text in self.accounts or text in self.aliases
-        ):
-            if text in self.aliases:
-                text = self.aliases[text]
+    def _resolve_account(self, text):
+        if text not in self.accounts and text not in self.aliases:
+            return None
+        original_text = text
+        self.readaccounts()
+        if text in self.aliases:
+            text = self.aliases[text]
+        if text in self.accounts:
+            return text
+        self.master.send_message(
+            True, "message", "Account " + original_text + " no longer exists"
+        )
+        self.get_last_updated_accounts()
+        return False
+
+    def _use_account(self, account):
+        if self.master.receipt.is_empty():
             self.master.send_message(
-                False, "infobox/account", json.dumps(self.accounts[text])
+                False, "infobox/account", json.dumps(self.accounts[account])
             )
             self.master.send_message(
                 True, "buttons", json.dumps({"special": "infobox"})
             )
             return True
-        if text in self.accounts or text in self.aliases:
-            if text in self.aliases:
-                text = self.aliases[text]
-            self.master.callhook("checkout", text)
-            self.master.callhook("endsession", text)
+        self.master.callhook("checkout", account)
+        self.master.callhook("endsession", account)
+        return True
+
+    # This handles the input
+    def input(self, text):
+        account = self._resolve_account(text)
+        if account is False:
             return True
+        if account is not None:
+            return self._use_account(account)
         command_handlers = {
             "adduseralias": lambda: self.messageandbuttons(
                 "askalias", "accounts", "What user do you want to alias?"
diff --git a/tests/js/kassa-buttons.test.js b/tests/js/kassa-buttons.test.js
index c418229..c96196e 100644
--- a/tests/js/kassa-buttons.test.js
+++ b/tests/js/kassa-buttons.test.js
@@ -55,6 +55,7 @@ test("accountsToButtons filters member types and marks negative balances", () =>
 
   assert.deepEqual(plain(helpers.accountsToButtons(accounts, ["alice"], ["bob"], "m")), [
     {
+      class: "account account-alice",
       display: "alice",
       fill: true,
       right: "-20.00",
@@ -64,6 +65,7 @@ test("accountsToButtons filters member types and marks negative balances", () =>
   ]);
   assert.deepEqual(plain(helpers.accountsToButtons(accounts, ["alice"], ["bob"], "o")), [
     {
+      class: "account account-bob",
       display: "bob",
       fill: true,
       right: "-2.00",
@@ -73,6 +75,7 @@ test("accountsToButtons filters member types and marks negative balances", () =>
   ]);
   assert.deepEqual(plain(helpers.accountsToButtons(accounts, ["alice"], ["bob"], "x")), [
     {
+      class: "account account-carol",
       display: "carol",
       fill: true,
       right: "3.50",
@@ -82,6 +85,30 @@ test("accountsToButtons filters member types and marks negative balances", () =>
   ]);
 });
 
+test("account button classes are safe for CSS selectors", () => {
+  const helpers = loadButtonHelpers();
+  const accounts = {
+    "alice@example": {amount: 1},
+  };
+
+  assert.equal(helpers.cssSafeClassName("alice@example"), "alice-example");
+  assert.deepEqual(plain(helpers.accountsToButtons(
+    accounts,
+    ["alice@example"],
+    [],
+    "m",
+  )), [
+    {
+      class: "account account-alice-example",
+      display: "alice@example",
+      fill: true,
+      right: "1.00",
+      rightclass: "alice@example",
+      text: "alice@example",
+    },
+  ]);
+});
+
 test("product button helpers include prices, stock and aliases for app pages", () => {
   const helpers = loadButtonHelpers();
   const products = {
diff --git a/tests/plugins/test_POS.py b/tests/plugins/test_POS.py
index 62cd8d1..71fe322 100644
--- a/tests/plugins/test_POS.py
+++ b/tests/plugins/test_POS.py
@@ -143,6 +143,28 @@ def test_makebon_uses_checkout_balance_snapshot_for_new_balance(self):
         assert b"Nieuw saldo: 15.00" in bon
         assert b"Nieuw saldo: 10.00" not in bon
 
+    def test_makebon_missing_account_uses_zero_balance(self):
+        self.POS.master.receipt = Mock(
+            receipt=[
+                {
+                    "product": "test",
+                    "beni": "TestAccountMissing",
+                    "count": 1,
+                    "total": 2.5,
+                    "description": "stale account sale",
+                }
+            ],
+            totals={"TestAccountMissing": -2.5},
+        )
+        self.POS.master.transID = 42
+        self.POS.master.accounts.accounts = {}
+        self.POS.master.accounts.checkout_balances = {}
+
+        bon = self.POS.makebon("TestAccountMissing")
+
+        assert b"stale account sale" in bon
+        assert b"Nieuw saldo: -2.50" in bon
+
     def test_makebon_cash_does_not_require_account(self):
         self.POS.master.receipt = Mock(
             receipt=[
diff --git a/tests/plugins/test_accounts.py b/tests/plugins/test_accounts.py
index 0be323d..78e40ce 100644
--- a/tests/plugins/test_accounts.py
+++ b/tests/plugins/test_accounts.py
@@ -50,6 +50,24 @@ def test_updateaccount_ignores_cash():
     master_mock.callhook.assert_not_called()
 
 
+@patch("time.strftime")
+def test_updateaccount_creates_missing_account(mock_strftime):
+    mock_strftime.return_value = "2026-06-09_21:02:10"
+    master_mock = Mock()
+    master_mock.transID = 481031730
+    acc = accounts("SID", master_mock)
+
+    acc.updateaccount("TestAccountMissing", -2.5)
+
+    assert acc.accounts["TestAccountMissing"] == {
+        "amount": -2.5,
+        "lastupdate": "2026-06-09_21:02:10",
+    }
+    master_mock.callhook.assert_called_with(
+        "balance", ("TestAccountMissing", 0, -2.5, 481031730)
+    )
+
+
 def test_readaccounts():
     master_mock = Mock()
     acc = accounts("SID", master_mock)
@@ -551,7 +569,8 @@ def test_input_existing_account():
     acc.aliases = {}
 
     # Test with existing account
-    acc.input("user1")
+    with patch.object(acc, "readaccounts"):
+        acc.input("user1")
     expected_calls = [
         call(False, "infobox/account", "{}"),
         call(True, "buttons", '{"special": "infobox"}'),
@@ -565,20 +584,67 @@ def test_input_alias_empty_receipt_and_checkout_paths():
     acc.accounts = {"user1": {"amount": 12.0}}
     acc.aliases = {"alias1": "user1"}
 
-    master_mock.receipt.is_empty.return_value = True
-    assert acc.input("alias1") is True
+    with patch.object(acc, "readaccounts"):
+        master_mock.receipt.is_empty.return_value = True
+        assert acc.input("alias1") is True
+        master_mock.send_message.assert_has_calls(
+            [
+                call(False, "infobox/account", '{"amount": 12.0}'),
+                call(True, "buttons", '{"special": "infobox"}'),
+            ]
+        )
+
+        master_mock.reset_mock()
+        master_mock.receipt.is_empty.return_value = False
+        assert acc.input("alias1") is True
+        master_mock.callhook.assert_has_calls(
+            [call("checkout", "user1"), call("endsession", "user1")]
+        )
+
+
+def test_input_stale_account_is_rejected_before_checkout():
+    master_mock = Mock()
+    master_mock.receipt.is_empty.return_value = False
+    acc = accounts("SID", master_mock)
+    acc.accounts = {"TestAccountMissing": {"amount": 12.0, "lastupdate": "old"}}
+    acc.aliases = {}
+
+    def clear_accounts():
+        acc.accounts = {}
+        acc.aliases = {}
+
+    with patch.object(acc, "readaccounts", side_effect=clear_accounts):
+        assert acc.input("TestAccountMissing") is True
+
+    master_mock.callhook.assert_not_called()
     master_mock.send_message.assert_has_calls(
         [
-            call(False, "infobox/account", '{"amount": 12.0}'),
-            call(True, "buttons", '{"special": "infobox"}'),
+            call(True, "message", "Account TestAccountMissing no longer exists"),
+            call(True, "nonmembers", "[]"),
         ]
     )
 
-    master_mock.reset_mock()
+
+def test_input_alias_to_stale_account_is_rejected_before_checkout():
+    master_mock = Mock()
     master_mock.receipt.is_empty.return_value = False
-    assert acc.input("alias1") is True
-    master_mock.callhook.assert_has_calls(
-        [call("checkout", "user1"), call("endsession", "user1")]
+    acc = accounts("SID", master_mock)
+    acc.accounts = {"user1": {"amount": 12.0, "lastupdate": "old"}}
+    acc.aliases = {"alias1": "user1"}
+
+    def clear_accounts():
+        acc.accounts = {}
+        acc.aliases = {"alias1": "user1"}
+
+    with patch.object(acc, "readaccounts", side_effect=clear_accounts):
+        assert acc.input("alias1") is True
+
+    master_mock.callhook.assert_not_called()
+    master_mock.send_message.assert_has_calls(
+        [
+            call(True, "message", "Account alias1 no longer exists"),
+            call(True, "nonmembers", "[]"),
+        ]
     )
 
 
diff --git a/www/kassa-buttons.js b/www/kassa-buttons.js
index ad25a3c..08b3c64 100644
--- a/www/kassa-buttons.js
+++ b/www/kassa-buttons.js
@@ -17,6 +17,10 @@
     return 0;
   }
 
+  function cssSafeClassName(value) {
+    return String(value).replace(/[^A-Za-z0-9_-]/g, "-");
+  }
+
   function rebuildProductIndexes(products, groups, productsWithoutBarcode) {
     Object.keys(groups).forEach(function(group) {
       delete groups[group];
@@ -79,6 +83,7 @@
       buttons.push({
         text: user,
         display: user,
+        class: "account account-" + cssSafeClassName(user),
         rightclass: extraclass,
         right: amount.toFixed(2),
         fill: true,
@@ -144,6 +149,7 @@
     commandsToButtons: commandsToButtons,
     compareDisplay: compareDisplay,
     compareTextReverse: compareTextReverse,
+    cssSafeClassName: cssSafeClassName,
     productGroupToButtons: productGroupToButtons,
     productsToButtons: productsToButtons,
     rebuildProductIndexes: rebuildProductIndexes,
diff --git a/www/mystyle.css b/www/mystyle.css
index 747821b..ce76258 100644
--- a/www/mystyle.css
+++ b/www/mystyle.css
@@ -427,6 +427,15 @@ font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
   left: 0;
   position: absolute;
 }
+.account {
+  background-position: center;
+  background-repeat: no-repeat;
+  background-size: cover;
+}
+.account .Buttontext,
+.account .extra {
+  text-shadow: 0 1px 2px #000;
+}
 .account.fullwidthButton {
   width: 9.75vw;
 }
diff --git a/www/spaceconsole/mystyle.css b/www/spaceconsole/mystyle.css
index 747821b..ce76258 100644
--- a/www/spaceconsole/mystyle.css
+++ b/www/spaceconsole/mystyle.css
@@ -427,6 +427,15 @@ font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
   left: 0;
   position: absolute;
 }
+.account {
+  background-position: center;
+  background-repeat: no-repeat;
+  background-size: cover;
+}
+.account .Buttontext,
+.account .extra {
+  text-shadow: 0 1px 2px #000;
+}
 .account.fullwidthButton {
   width: 9.75vw;
 }
diff --git a/www/spaceconsole/stom.css b/www/spaceconsole/stom.css
index cffde6c..d1617a7 100644
--- a/www/spaceconsole/stom.css
+++ b/www/spaceconsole/stom.css
@@ -446,6 +446,15 @@ font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
   left: 0;
   position: absolute;
 }
+.account {
+  background-position: center;
+  background-repeat: no-repeat;
+  background-size: cover;
+}
+.account .Buttontext,
+.account .extra {
+  text-shadow: 0 1px 2px #000;
+}
 .account.fullwidthButton {
   width: 9.75vw;
 }
diff --git a/www/stom.css b/www/stom.css
index cffde6c..d1617a7 100644
--- a/www/stom.css
+++ b/www/stom.css
@@ -446,6 +446,15 @@ font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
   left: 0;
   position: absolute;
 }
+.account {
+  background-position: center;
+  background-repeat: no-repeat;
+  background-size: cover;
+}
+.account .Buttontext,
+.account .extra {
+  text-shadow: 0 1px 2px #000;
+}
 .account.fullwidthButton {
   width: 9.75vw;
 }