diff --git a/cafe-management-sys/src/components/common/ResponsiveTable.jsx b/cafe-management-sys/src/components/common/ResponsiveTable.jsx
index 817616f..ea8890c 100644
--- a/cafe-management-sys/src/components/common/ResponsiveTable.jsx
+++ b/cafe-management-sys/src/components/common/ResponsiveTable.jsx
@@ -1,4 +1,4 @@
-import React, { useEffect, useState } from 'react';
+import React, { useEffect, useMemo, useState } from 'react';
 import {
   Box,
   Table,
@@ -7,12 +7,14 @@ import {
   TableContainer,
   TableHead,
   TableRow,
+  TableSortLabel,
   Typography,
   IconButton,
   CircularProgress,
 } from '@mui/material';
 import ChevronLeft from '@mui/icons-material/ChevronLeft';
 import ChevronRight from '@mui/icons-material/ChevronRight';
+import { sortRows, toggleSort } from '../../utils/sortable';
 
 const PAGE_SIZE = 25;
 
@@ -37,7 +39,13 @@ const ResponsiveTable = ({
   emptyMessage = 'No records found',
 }) => {
   const [page, setPage] = useState(0);
-  const pageCount = Math.max(1, Math.ceil((rows.length || 0) / PAGE_SIZE));
+  const [sort, setSort] = useState(null);
+
+  const sortableRows = useMemo(
+    () => (sort ? sortRows(rows, sort.key, sort.dir) : rows),
+    [rows, sort]
+  );
+  const pageCount = Math.max(1, Math.ceil((sortableRows.length || 0) / PAGE_SIZE));
 
   // Reset to the first page whenever the record set changes (search/filter).
   useEffect(() => {
@@ -46,7 +54,7 @@ const ResponsiveTable = ({
 
   const safePage = Math.min(page, pageCount - 1);
   const start = safePage * PAGE_SIZE;
-  const visible = rows.slice(start, start + PAGE_SIZE);
+  const visible = sortableRows.slice(start, start + PAGE_SIZE);
 
   if (loading) {
     return (
@@ -56,7 +64,7 @@ const ResponsiveTable = ({
     );
   }
 
-  if (!rows.length) {
+  if (!sortableRows.length) {
     return (
       <Box sx={{ py: 4 }}>
         <Typography variant="body2" color="text.secondary" align="center">
@@ -75,7 +83,17 @@ const ResponsiveTable = ({
             <TableRow>
               {columns.map((col, i) => (
                 <TableCell key={i} align={col.align || 'left'}>
-                  {col.label}
+                  {col.sortKey ? (
+                    <TableSortLabel
+                      active={sort?.key === col.sortKey}
+                      direction={sort?.key === col.sortKey ? sort.dir : 'asc'}
+                      onClick={() => setSort((s) => toggleSort(s, col.sortKey))}
+                    >
+                      {col.label}
+                    </TableSortLabel>
+                  ) : (
+                    col.label
+                  )}
                 </TableCell>
               ))}
             </TableRow>
@@ -90,7 +108,7 @@ const ResponsiveTable = ({
       </Box>
 
       {/* Pagination */}
-      {rows.length > PAGE_SIZE && (
+      {sortableRows.length > PAGE_SIZE && (
         <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', px: 2, py: 1.5 }}>
           <Typography variant="body2" color="text.secondary">
             {start + 1}–{Math.min(start + PAGE_SIZE, rows.length)} of {rows.length}
diff --git a/cafe-management-sys/src/pages/admin/AdminInvoices.jsx b/cafe-management-sys/src/pages/admin/AdminInvoices.jsx
index 135a045..c1f5ccf 100644
--- a/cafe-management-sys/src/pages/admin/AdminInvoices.jsx
+++ b/cafe-management-sys/src/pages/admin/AdminInvoices.jsx
@@ -169,12 +169,12 @@ const AdminInvoices = () => {
           loading={loading}
           emptyMessage="No invoices"
           columns={[
-            { label: 'Invoice #' },
-            { label: 'Date' },
+            { label: 'Invoice #', sortKey: 'invoiceNumber' },
+            { label: 'Date', sortKey: 'issuedAt' },
             { label: 'Status' },
             { label: 'Taxable', align: 'right' },
             { label: 'CGST+SGST', align: 'right' },
-            { label: 'Total', align: 'right' },
+            { label: 'Total', align: 'right', sortKey: 'grandTotal' },
             { label: '', align: 'center' },
           ]}
           renderRow={(inv) => {
diff --git a/cafe-management-sys/src/pages/admin/AdminOrders.jsx b/cafe-management-sys/src/pages/admin/AdminOrders.jsx
index cf7be1b..4bf6b79 100644
--- a/cafe-management-sys/src/pages/admin/AdminOrders.jsx
+++ b/cafe-management-sys/src/pages/admin/AdminOrders.jsx
@@ -315,12 +315,12 @@ const AdminOrders = () => {
           emptyMessage="No orders found"
           columns={[
             { label: '', align: 'center' },
-            { label: 'Order #' },
+            { label: 'Order #', sortKey: 'orderNumber' },
             { label: 'Customer' },
             { label: 'Items' },
-            { label: 'Total' },
+            { label: 'Total', sortKey: 'total' },
             { label: 'Status' },
-            { label: 'Date' },
+            { label: 'Date', sortKey: 'createdAt' },
             { label: '', align: 'center' },
           ]}
           renderRow={(order) => (
diff --git a/cafe-management-sys/src/utils/sortable.js b/cafe-management-sys/src/utils/sortable.js
new file mode 100644
index 0000000..380e825
--- /dev/null
+++ b/cafe-management-sys/src/utils/sortable.js
@@ -0,0 +1,27 @@
+const isNumeric = (v) => v != null && v !== '' && !Number.isNaN(Number(v));
+
+export const compareValues = (a, b) => {
+  const an = isNumeric(a);
+  const bn = isNumeric(b);
+  if (an && bn) return Number(a) - Number(b);
+  if (a == null || a === '') return 1; // sort empties last
+  if (b == null || b === '') return -1;
+  return String(a).localeCompare(String(b));
+};
+
+export const sortRows = (rows = [], key, dir = 'asc') => {
+  if (!key) return [...rows];
+  const factor = dir === 'desc' ? -1 : 1;
+  const isEmpty = (v) => v == null || v === '';
+  return [...rows].sort((x, y) => {
+    const a = x?.[key];
+    const b = y?.[key];
+    if (isEmpty(a) !== isEmpty(b)) return isEmpty(a) ? 1 : -1; // empties last always
+    return factor * compareValues(a, b);
+  });
+};
+
+export const toggleSort = (current, key) =>
+  current && current.key === key && current.dir === 'asc'
+    ? { key, dir: 'desc' }
+    : { key, dir: 'asc' };
\ No newline at end of file
diff --git a/cafe-management-sys/src/utils/sortable.test.js b/cafe-management-sys/src/utils/sortable.test.js
new file mode 100644
index 0000000..65c9f20
--- /dev/null
+++ b/cafe-management-sys/src/utils/sortable.test.js
@@ -0,0 +1,41 @@
+import { describe, it, expect } from 'vitest';
+import { compareValues, sortRows, toggleSort } from './sortable';
+
+describe('compareValues', () => {
+  it('sorts numbers numerically and strings lexically', () => {
+    expect(compareValues(2, 10)).toBeLessThan(0);
+    expect(compareValues('b', 'a')).toBeGreaterThan(0);
+  });
+  it('puts empty/missing values last', () => {
+    expect(compareValues('', 'a')).toBeGreaterThan(0);
+    expect(compareValues(null, 'a')).toBeGreaterThan(0);
+  });
+});
+
+describe('sortRows', () => {
+  const rows = [
+    { id: 'a', orderNumber: 'ORD-0002', total: 100 },
+    { id: 'b', orderNumber: 'ORD-0010', total: 50 },
+    { id: 'c', orderNumber: 'ORD-0001', total: null },
+  ];
+  it('sorts ascending (string-aware, not numeric-mangled)', () => {
+    expect(sortRows(rows, 'orderNumber', 'asc').map((r) => r.id)).toEqual(['c', 'a', 'b']);
+  });
+  it('sorts totals numerically with nulls last', () => {
+    expect(sortRows(rows, 'total', 'asc').map((r) => r.id)).toEqual(['b', 'a', 'c']);
+    expect(sortRows(rows, 'total', 'desc').map((r) => r.id)).toEqual(['a', 'b', 'c']);
+  });
+  it('returns a copy by default and does not mutate input', () => {
+    const copy = sortRows(rows, 'total');
+    expect(copy).not.toBe(rows);
+    expect(rows[0].id).toBe('a');
+  });
+});
+
+describe('toggleSort', () => {
+  it('toggles asc->desc and switches keys', () => {
+    expect(toggleSort({ key: 'total', dir: 'asc' }, 'total')).toEqual({ key: 'total', dir: 'desc' });
+    expect(toggleSort({ key: 'total', dir: 'desc' }, 'total')).toEqual({ key: 'total', dir: 'asc' });
+    expect(toggleSort(null, 'date')).toEqual({ key: 'date', dir: 'asc' });
+  });
+});
\ No newline at end of file