diff --git a/app/src/navigation/RootNavigator.tsx b/app/src/navigation/RootNavigator.tsx
index 7bce428..bc9356c 100644
--- a/app/src/navigation/RootNavigator.tsx
+++ b/app/src/navigation/RootNavigator.tsx
@@ -20,12 +20,14 @@ import { ProfileScreen } from '@/screens/ProfileScreen';
 import { VehiclesScreen } from '@/screens/VehiclesScreen';
 import { PaymentMethodsScreen } from '@/screens/PaymentMethodsScreen';
 import { NotificationsScreen } from '@/screens/NotificationsScreen';
+import { StartSessionScreen } from '@/screens/StartSessionScreen';
 import { useTheme } from '@/theme/ThemeContext';
 import type { Zone } from 'parksmarter-client';
 
 export type RootStackParamList = {
   Tabs: undefined;
   MeterDetail: { zone: Zone };
+  StartSession: { zone: Zone };
   About: undefined;
   Profile: undefined;
   Vehicles: undefined;
@@ -111,6 +113,11 @@ export function RootNavigator() {
             component={MeterDetailScreen}
             options={{ title: 'Meter' }}
           />
+          <Stack.Screen
+            name="StartSession"
+            component={StartSessionScreen}
+            options={{ title: 'Start session' }}
+          />
           <Stack.Screen name="About" component={AboutScreen} options={{ title: 'About' }} />
           <Stack.Screen name="Profile" component={ProfileScreen} options={{ title: 'Profile' }} />
           <Stack.Screen name="Vehicles" component={VehiclesScreen} options={{ title: 'Vehicles' }} />
diff --git a/app/src/screens/AboutScreen.tsx b/app/src/screens/AboutScreen.tsx
index f133e87..6bfc85f 100644
--- a/app/src/screens/AboutScreen.tsx
+++ b/app/src/screens/AboutScreen.tsx
@@ -10,10 +10,12 @@ import {
   View,
 } from 'react-native';
 import { ps } from '@/api/client';
+import { useTheme } from '@/theme/ThemeContext';
 
 const TAPS_TO_UNLOCK = 7;
 
 export function AboutScreen() {
+  const { colors } = useTheme();
   const [about, setAbout] = useState<string | null>(null);
   const [showJoel, setShowJoel] = useState(false);
   const taps = useRef(0);
@@ -37,14 +39,14 @@ export function AboutScreen() {
   };
 
   return (
-    <ScrollView contentContainerStyle={styles.container}>
+    <ScrollView style={{ backgroundColor: colors.bg }} contentContainerStyle={styles.container}>
       <Pressable onPress={onTitleTap}>
-        <Text style={styles.title}>About BigBrainParking</Text>
+        <Text style={[styles.title, { color: colors.text }]}>About BigBrainParking</Text>
       </Pressable>
 
-      <Text style={styles.body}>{about ?? 'Loading…'}</Text>
+      <Text style={[styles.body, { color: colors.text }]}>{about ?? 'Loading…'}</Text>
 
-      <Text style={styles.meta}>
+      <Text style={[styles.meta, { color: colors.subtext }]}>
         Unofficial, de-Googled client for ParkSmarter. Not affiliated with IPS Group.
       </Text>
 
diff --git a/app/src/screens/MeterDetailScreen.tsx b/app/src/screens/MeterDetailScreen.tsx
index 2aeb02a..4fb3199 100644
--- a/app/src/screens/MeterDetailScreen.tsx
+++ b/app/src/screens/MeterDetailScreen.tsx
@@ -1,7 +1,8 @@
 import React, { useState } from 'react';
 import { Alert, ScrollView, StyleSheet, Text, TouchableOpacity, View } from 'react-native';
 import type { RouteProp } from '@react-navigation/native';
-import { useRoute } from '@react-navigation/native';
+import { useNavigation, useRoute } from '@react-navigation/native';
+import type { NativeStackNavigationProp } from '@react-navigation/native-stack';
 import type { RootStackParamList } from '@/navigation/RootNavigator';
 import { saveKiosk, toSavedKiosk } from '@/features/favorites/favoritesStore';
 import { useTheme } from '@/theme/ThemeContext';
@@ -39,8 +40,11 @@ function policyMeta(p: SpacePolicy): { title: string; rate?: string; color?: str
   return { title, rate, color };
 }
 
+type Nav = NativeStackNavigationProp<RootStackParamList>;
+
 export function MeterDetailScreen() {
   const { colors } = useTheme();
+  const navigation = useNavigation<Nav>();
   const { params } = useRoute<DetailRoute>();
   const z = params.zone;
   const [saved, setSaved] = useState(false);
@@ -122,12 +126,7 @@ export function MeterDetailScreen() {
 
       <TouchableOpacity
         style={[styles.button, { backgroundColor: colors.primary }]}
-        onPress={() =>
-          Alert.alert(
-            'Start session',
-            'Starting a paid session is a real charge — this flow (vehicle + duration + card selection) is wired to postStartParkingSession and will be enabled after review.',
-          )
-        }
+        onPress={() => navigation.navigate('StartSession', { zone: z })}
       >
         <Text style={[styles.buttonText, { color: '#fff' }]}>Start parking session</Text>
       </TouchableOpacity>
diff --git a/app/src/screens/StartSessionScreen.tsx b/app/src/screens/StartSessionScreen.tsx
new file mode 100644
index 0000000..3e48b1e
--- /dev/null
+++ b/app/src/screens/StartSessionScreen.tsx
@@ -0,0 +1,321 @@
+import React, { useCallback, useEffect, useMemo, useState } from 'react';
+import {
+  ActivityIndicator,
+  Alert,
+  FlatList,
+  ScrollView,
+  StyleSheet,
+  Text,
+  TouchableOpacity,
+  View,
+} from 'react-native';
+import type { RouteProp } from '@react-navigation/native';
+import { useNavigation, useRoute } from '@react-navigation/native';
+import type { NativeStackNavigationProp } from '@react-navigation/native-stack';
+import { ps } from '@/api/client';
+import { useTheme } from '@/theme/ThemeContext';
+import { scheduleExpiryReminder } from '@/notifications/localReminders';
+import type { RootStackParamList } from '@/navigation/RootNavigator';
+import type {
+  CreditCardDetail,
+  ParkingDetail,
+  VehicleDetail,
+} from 'parksmarter-client';
+
+type SessionRoute = RouteProp<RootStackParamList, 'StartSession'>;
+type Nav = NativeStackNavigationProp<RootStackParamList>;
+
+function fmtDuration(min?: number): string {
+  if (!min) return '';
+  const h = Math.floor(min / 60);
+  const m = min % 60;
+  return h ? (m ? `${h}h ${m}m` : `${h}h`) : `${m}m`;
+}
+const money = (v?: string | number) => `$${Number(v ?? 0).toFixed(2)}`;
+
+/** Parse the API's "MM-DD-YYYY hh:mm AM" end-time string into a Date for reminders. */
+function parseApiTime(s?: string): Date | null {
+  if (!s) return null;
+  const m = s.match(/(\d{2})-(\d{2})-(\d{4})\s+(\d{1,2}):(\d{2})\s*(AM|PM)/i);
+  if (!m) return null;
+  let hr = parseInt(m[4], 10);
+  const pm = /pm/i.test(m[6]);
+  if (pm && hr !== 12) hr += 12;
+  if (!pm && hr === 12) hr = 0;
+  return new Date(+m[3], +m[1] - 1, +m[2], hr, +m[5]);
+}
+
+export function StartSessionScreen() {
+  const { colors } = useTheme();
+  const navigation = useNavigation<Nav>();
+  const { zone } = useRoute<SessionRoute>().params;
+  const space = zone.Spaces?.[0];
+
+  const [vehicles, setVehicles] = useState<VehicleDetail[]>([]);
+  const [cards, setCards] = useState<CreditCardDetail[]>([]);
+  const [vehicleId, setVehicleId] = useState<number | undefined>();
+  const [cardId, setCardId] = useState<number | undefined>();
+  const [ladder, setLadder] = useState<ParkingDetail[]>([]);
+  const [selIdx, setSelIdx] = useState(0);
+  const [loading, setLoading] = useState(true);
+  const [paying, setPaying] = useState(false);
+
+  // Load the account's vehicles + cards and pick the defaults.
+  useEffect(() => {
+    ps.getUserDetail()
+      .then((u) => {
+        const vs = u.VehicleDetails ?? [];
+        const cs = u.CreditCardDetails ?? [];
+        setVehicles(vs);
+        setCards(cs);
+        const defV = vs.find((v) => String(v.IsDefault) === 'true') ?? vs[0];
+        const defC = cs.find((c) => String(c.CCDefault) === 'true') ?? cs[0];
+        setVehicleId(defV?.VehicleID as number | undefined);
+        setCardId(defC?.CCID as number | undefined);
+      })
+      .catch(() => {});
+  }, []);
+
+  // (Re)fetch the price ladder whenever the vehicle changes — rates can vary by vehicle.
+  const loadLadder = useCallback(async () => {
+    if (vehicleId == null || space?.SpaceId == null) return;
+    setLoading(true);
+    try {
+      const est = await ps.getParkingEstimateMulti({
+        zoneId: zone.ZoneId!,
+        spaceId: space.SpaceId!,
+        customerId: zone.CustomerId!,
+        vehicleId,
+      });
+      const details = est.ParkingDetail ?? [];
+      setLadder(details);
+      setSelIdx((i) => Math.min(i, Math.max(0, details.length - 1)));
+    } finally {
+      setLoading(false);
+    }
+  }, [vehicleId, space?.SpaceId, zone.ZoneId, zone.CustomerId]);
+
+  useEffect(() => {
+    void loadLadder();
+  }, [loadLadder]);
+
+  const selected = ladder[selIdx];
+
+  // Detect a free prefix (e.g., inside a "Free until 6:15 AM" policy window).
+  const freeInfo = useMemo(() => {
+    const firstPaid = ladder.findIndex((d) => Number(d.ParkingCost) > 0);
+    if (firstPaid > 0) {
+      return { until: ladder[firstPaid - 1]?.EndTime, minutes: ladder[firstPaid - 1]?.Minutes };
+    }
+    return null;
+  }, [ladder]);
+
+  const total = selected
+    ? Number(selected.ParkingCost ?? 0) + Number(selected.TransactionFee ?? 0)
+    : 0;
+
+  const onPay = () => {
+    if (!selected || cardId == null || vehicleId == null) {
+      Alert.alert('Missing info', 'Pick a vehicle, duration, and card first.');
+      return;
+    }
+    Alert.alert(
+      'Confirm payment',
+      `Park at ${zone.ZoneName} for ${fmtDuration(selected.Minutes)}.\n\n` +
+        `Parking ${money(selected.ParkingCost)}` +
+        (Number(selected.TransactionFee) > 0 ? ` + fee ${money(selected.TransactionFee)}` : '') +
+        `\nTotal: ${money(total)}\n\nThis charges your card now.`,
+      [
+        { text: 'Cancel', style: 'cancel' },
+        { text: `Pay ${money(total)}`, style: 'default', onPress: doStart },
+      ],
+    );
+  };
+
+  const doStart = async () => {
+    if (!selected) return;
+    setPaying(true);
+    try {
+      const res = await ps.startParkingSession({
+        creditCardId: cardId!,
+        vehicleId: vehicleId!,
+        zoneId: zone.ZoneId!,
+        spaceId: space!.SpaceId!,
+        customerId: zone.CustomerId!,
+        startTime: selected.StartTime!,
+        endTime: selected.EndTime!,
+        minutesToPurchase: selected.Minutes!,
+        parkingCost: Number(selected.ParkingCost ?? 0),
+        transactionFee: Number(selected.TransactionFee ?? 0),
+        minCreditAmount: zone.MinimumAmount,
+        meterTypeId: zone.MeterTypeId!,
+      });
+      // Schedule the local expiry reminder from the purchased end time.
+      const end = parseApiTime(selected.EndTime);
+      if (end) {
+        await scheduleExpiryReminder({
+          transactionId: (res as any)?.TransactionID ?? Date.now(),
+          zoneName: zone.ZoneName ?? 'Parking',
+          endTime: end,
+        });
+      }
+      Alert.alert('Parked!', `Session started at ${zone.ZoneName}.`, [
+        { text: 'OK', onPress: () => navigation.navigate('Tabs') },
+      ]);
+    } catch (e: any) {
+      Alert.alert('Could not start session', e?.serverMessage ?? e?.message ?? 'error');
+    } finally {
+      setPaying(false);
+    }
+  };
+
+  if (loading && !ladder.length) {
+    return (
+      <View style={[styles.center, { backgroundColor: colors.bg }]}>
+        <ActivityIndicator color={colors.primary} />
+      </View>
+    );
+  }
+
+  const Chip = ({
+    active,
+    label,
+    onPress,
+  }: {
+    active: boolean;
+    label: string;
+    onPress: () => void;
+  }) => (
+    <TouchableOpacity
+      onPress={onPress}
+      style={[
+        styles.chip,
+        { borderColor: active ? colors.primary : colors.border, backgroundColor: active ? colors.primary : colors.card },
+      ]}
+    >
+      <Text style={{ color: active ? '#fff' : colors.text, fontWeight: '600' }}>{label}</Text>
+    </TouchableOpacity>
+  );
+
+  return (
+    <ScrollView style={{ backgroundColor: colors.bg }} contentContainerStyle={{ padding: 16 }}>
+      <Text style={[styles.zone, { color: colors.text }]}>{zone.ZoneName}</Text>
+      <Text style={[styles.sub, { color: colors.subtext }]}>
+        {zone.ZoneLocation ?? space?.SpaceName ?? ''}
+      </Text>
+
+      <Text style={[styles.label, { color: colors.subtext }]}>Vehicle</Text>
+      <View style={styles.chipRow}>
+        {vehicles.map((v) => (
+          <Chip
+            key={String(v.VehicleID)}
+            active={v.VehicleID === vehicleId}
+            label={`${v.VehicleAlias || v.VehiclePlate} `}
+            onPress={() => setVehicleId(v.VehicleID as number)}
+          />
+        ))}
+      </View>
+
+      <Text style={[styles.label, { color: colors.subtext }]}>Duration</Text>
+      <FlatList
+        horizontal
+        data={ladder}
+        keyExtractor={(d, i) => String(d.Minutes ?? i)}
+        showsHorizontalScrollIndicator={false}
+        renderItem={({ item, index }) => (
+          <Chip
+            active={index === selIdx}
+            label={`${fmtDuration(item.Minutes)} · ${money(item.ParkingCost)}`}
+            onPress={() => setSelIdx(index)}
+          />
+        )}
+      />
+
+      <Text style={[styles.label, { color: colors.subtext }]}>Card</Text>
+      <View style={styles.chipRow}>
+        {cards.map((c) => (
+          <Chip
+            key={String(c.CCID)}
+            active={c.CCID === cardId}
+            label={`${c.CCAlias || 'Card'} ••${c.CCLastFour ?? ''}`}
+            onPress={() => setCardId(c.CCID as number)}
+          />
+        ))}
+        {cards.length === 0 ? (
+          <Text style={{ color: colors.subtext }}>No cards on file.</Text>
+        ) : null}
+      </View>
+
+      {freeInfo ? (
+        <View style={[styles.freeBanner, { backgroundColor: '#e8f5e9' }]}>
+          <Text style={{ color: '#2e7d32', fontWeight: '600' }}>
+            Free until {freeInfo.until} ({fmtDuration(freeInfo.minutes)}), then charged.
+          </Text>
+        </View>
+      ) : null}
+
+      {selected ? (
+        <View style={[styles.quote, { backgroundColor: colors.card }]}>
+          <Row label="Duration" value={fmtDuration(selected.Minutes)} colors={colors} />
+          <Row label="Ends" value={selected.EndTime ?? ''} colors={colors} />
+          <Row label="Parking" value={money(selected.ParkingCost)} colors={colors} />
+          {Number(selected.TransactionFee) > 0 ? (
+            <Row label="Fee" value={money(selected.TransactionFee)} colors={colors} />
+          ) : null}
+          <Row label="Total" value={money(total)} bold colors={colors} />
+        </View>
+      ) : null}
+
+      <TouchableOpacity
+        style={[styles.payBtn, { backgroundColor: colors.primary, opacity: paying ? 0.6 : 1 }]}
+        disabled={paying || !selected}
+        onPress={onPay}
+      >
+        <Text style={styles.payText}>
+          {paying ? 'Starting…' : `Pay ${money(total)} & start`}
+        </Text>
+      </TouchableOpacity>
+    </ScrollView>
+  );
+}
+
+function Row({
+  label,
+  value,
+  bold,
+  colors,
+}: {
+  label: string;
+  value: string;
+  bold?: boolean;
+  colors: { text: string; subtext: string };
+}) {
+  return (
+    <View style={styles.quoteRow}>
+      <Text style={{ color: colors.subtext }}>{label}</Text>
+      <Text style={{ color: colors.text, fontWeight: bold ? '800' : '600', fontSize: bold ? 18 : 15 }}>
+        {value}
+      </Text>
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  center: { flex: 1, alignItems: 'center', justifyContent: 'center' },
+  zone: { fontSize: 24, fontWeight: '700' },
+  sub: { marginBottom: 8 },
+  label: { fontSize: 13, fontWeight: '600', marginTop: 18, marginBottom: 8 },
+  chipRow: { flexDirection: 'row', flexWrap: 'wrap', gap: 8 },
+  chip: {
+    borderWidth: 1.5,
+    borderRadius: 20,
+    paddingHorizontal: 14,
+    paddingVertical: 9,
+    marginRight: 8,
+  },
+  freeBanner: { borderRadius: 10, padding: 12, marginTop: 16 },
+  quote: { borderRadius: 12, padding: 16, marginTop: 16 },
+  quoteRow: { flexDirection: 'row', justifyContent: 'space-between', paddingVertical: 5 },
+  payBtn: { borderRadius: 12, padding: 18, alignItems: 'center', marginTop: 20 },
+  payText: { color: '#fff', fontWeight: '800', fontSize: 17 },
+});