diff --git a/client/src/components/Budget/CostsPanel.filtering.test.tsx b/client/src/components/Budget/CostsPanel.filtering.test.tsx
new file mode 100644
index 000000000..fe073c96e
--- /dev/null
+++ b/client/src/components/Budget/CostsPanel.filtering.test.tsx
@@ -0,0 +1,170 @@
+// FE-W5COSTS-014 to FE-W5COSTS-019 and FE-W5COSTS-076: filtering the Costs ledger
+import userEvent from '@testing-library/user-event';
+import { http, HttpResponse } from 'msw';
+import { buildBudgetItem, buildTrip, buildUser } from '../../../tests/helpers/factories';
+import { server } from '../../../tests/helpers/msw/server';
+import { fireEvent, render, screen, within } from '../../../tests/helpers/render';
+import { resetAllStores, seedStore } from '../../../tests/helpers/store';
+import { useAuthStore } from '../../store/authStore';
+import { useSettingsStore } from '../../store/settingsStore';
+import { useTripStore } from '../../store/tripStore';
+import type { BudgetItem } from '../../types';
+import CostsPanel from './CostsPanel';
+
+const tripMembers = [
+  { id: 1, username: 'alice', avatar_url: null },
+  { id: 2, username: 'bob', avatar_url: null },
+];
+
+type Payment = {
+  id: number;
+  from_user_id: number;
+  to_user_id: number;
+  amount: number;
+  created_at?: string;
+  settled_at?: string | null;
+};
+type MemberFixture = { user_id: number; username?: string };
+const expense = (over: Partial<Omit<BudgetItem, 'members'>> & { members?: MemberFixture[] }): BudgetItem =>
+  ({ ...buildBudgetItem({ trip_id: 1 }), payers: [], members: [], ...over }) as unknown as BudgetItem;
+
+function mount(items: BudgetItem[], settlement: { settlements?: Payment[] } = {}) {
+  server.use(
+    http.get('/api/trips/1/budget', () => HttpResponse.json({ items })),
+    http.get('/api/trips/1/budget/settlement', () =>
+      HttpResponse.json({ balances: [], flows: [], settlements: [], ...settlement })
+    )
+  );
+  return render(<CostsPanel tripId={1} tripMembers={tripMembers} />);
+}
+
+// Alice is the signed-in user; the euro display currency keeps FX an identity.
+function seedAlice() {
+  resetAllStores();
+  seedStore(useTripStore, { trip: buildTrip({ id: 1, currency: 'EUR' }) });
+  seedStore(useAuthStore, { user: buildUser({ id: 1, username: 'alice' }), isAuthenticated: true });
+  seedStore(useSettingsStore, { settings: { ...useSettingsStore.getState().settings, default_currency: 'EUR' } });
+}
+
+const dinner = () =>
+  expense({
+    id: 101,
+    name: 'Dinner',
+    category: 'food',
+    total_price: 90,
+    expense_date: '2025-06-15',
+    payers: [{ user_id: 1, amount: 90 }],
+    members: [
+      { user_id: 1, username: 'alice' },
+      { user_id: 2, username: 'bob' },
+    ],
+  });
+const taxi = () =>
+  expense({
+    id: 102,
+    name: 'Taxi',
+    category: 'transport',
+    total_price: 30,
+    expense_date: '2025-06-16',
+    payers: [{ user_id: 2, amount: 30 }],
+    members: [
+      { user_id: 1, username: 'alice' },
+      { user_id: 2, username: 'bob' },
+    ],
+  });
+
+describe('CostsPanel — filtering the ledger', () => {
+  beforeEach(seedAlice);
+
+  const payment: Payment = { id: 7, from_user_id: 2, to_user_id: 1, amount: 30, created_at: '2025-06-16 10:00:00' };
+  // The payment comes with the settlement, which can arrive after the expenses: a filter is
+  // only tested against it once both are on screen.
+  const ledgerLoaded = async () => {
+    await screen.findByText('Taxi');
+    await screen.findByText('Payment');
+  };
+
+  it('FE-W5COSTS-014: "Paid by me" keeps only the expenses I fronted', async () => {
+    mount([dinner(), taxi()], { settlements: [payment] });
+
+    await ledgerLoaded();
+    fireEvent.click(screen.getByRole('button', { name: 'Filter' }));
+    fireEvent.click(screen.getByRole('button', { name: 'Paid by me' }));
+
+    expect(screen.getByText('Dinner')).toBeInTheDocument();
+    expect(screen.queryByText('Taxi')).not.toBeInTheDocument();
+    // A transfer I'm part of stays visible under "mine".
+    expect(screen.getByText('Payment')).toBeInTheDocument();
+  });
+
+  it('FE-W5COSTS-015: "I\'m owed" keeps the expenses I am net positive on and drops payments', async () => {
+    mount([dinner(), taxi()], { settlements: [payment] });
+
+    await ledgerLoaded();
+    fireEvent.click(screen.getByRole('button', { name: 'Filter' }));
+    fireEvent.click(screen.getByRole('button', { name: "I'm owed" }));
+
+    expect(screen.getByText('Dinner')).toBeInTheDocument();
+    expect(screen.queryByText('Taxi')).not.toBeInTheDocument();
+    expect(screen.queryByText('Payment')).not.toBeInTheDocument();
+  });
+
+  it('FE-W5COSTS-016: the category filter narrows the ledger and hides payments', async () => {
+    mount([dinner(), taxi()], { settlements: [payment] });
+
+    await ledgerLoaded();
+    fireEvent.click(screen.getByRole('button', { name: 'Filter' }));
+    fireEvent.click(within(screen.getByRole('menu')).getByRole('button', { name: 'Transport' }));
+
+    expect(screen.getByText('Taxi')).toBeInTheDocument();
+    expect(screen.queryByText('Dinner')).not.toBeInTheDocument();
+    expect(screen.queryByText('Payment')).not.toBeInTheDocument();
+  });
+
+  it('FE-W5COSTS-017: picking a single day banners it with that day’s total', async () => {
+    mount([dinner(), taxi()], { settlements: [payment] });
+
+    await ledgerLoaded();
+    fireEvent.click(screen.getByRole('button', { name: 'Filter' }));
+    fireEvent.click(within(screen.getByRole('menu')).getByRole('button', { name: 'Sun, Jun 15' }));
+
+    expect(screen.getByText('Sunday, June 15')).toBeInTheDocument();
+    expect(screen.getByText('1 expense')).toBeInTheDocument();
+    expect(screen.getByText('Dinner')).toBeInTheDocument();
+    expect(screen.queryByText('Taxi')).not.toBeInTheDocument();
+    // The 16th carries the payment, so it is filtered out with the day too.
+    expect(screen.queryByText('Payment')).not.toBeInTheDocument();
+  });
+
+  it('FE-W5COSTS-076: a payment groups by its own settled day, not the day it was recorded', async () => {
+    // Recorded (created_at) on the 16th, but settled on the 15th — the ledger
+    // must follow settled_at, the same way it already follows expense_date over
+    // an expense's own created_at.
+    mount([dinner(), taxi()], { settlements: [{ ...payment, settled_at: '2025-06-15' }] });
+
+    await ledgerLoaded();
+    fireEvent.click(screen.getByRole('button', { name: 'Filter' }));
+    fireEvent.click(within(screen.getByRole('menu')).getByRole('button', { name: 'Sun, Jun 15' }));
+
+    expect(screen.getByText('Dinner')).toBeInTheDocument();
+    expect(screen.queryByText('Taxi')).not.toBeInTheDocument();
+    expect(screen.getByText('Payment')).toBeInTheDocument();
+  });
+
+  it('FE-W5COSTS-018: expenses without a date are grouped under "No date"', async () => {
+    mount([expense({ id: 120, name: 'Souvenirs', category: 'shopping', total_price: 12, expense_date: null })]);
+
+    expect(await screen.findByText('No date')).toBeInTheDocument();
+  });
+
+  it('FE-W5COSTS-019: a search with no hits shows the no-match copy', async () => {
+    const user = userEvent.setup();
+    mount([dinner()]);
+
+    await screen.findByText('Dinner');
+    await user.type(screen.getByPlaceholderText('Search expenses…'), 'zzz');
+
+    expect(screen.getByText('No expenses match your search.')).toBeInTheDocument();
+    expect(screen.queryByText('Dinner')).not.toBeInTheDocument();
+  });
+});
diff --git a/client/src/components/Budget/CostsPanel.formerParticipants.test.tsx b/client/src/components/Budget/CostsPanel.formerParticipants.test.tsx
new file mode 100644
index 000000000..9c7970b7b
--- /dev/null
+++ b/client/src/components/Budget/CostsPanel.formerParticipants.test.tsx
@@ -0,0 +1,68 @@
+// FE-W5COSTS-097: someone who left the trip in the Costs panel (#2604)
+import { http, HttpResponse } from 'msw';
+import { buildBudgetItem, buildTrip, buildUser } from '../../../tests/helpers/factories';
+import { server } from '../../../tests/helpers/msw/server';
+import { render, screen, waitFor } from '../../../tests/helpers/render';
+import { resetAllStores, seedStore } from '../../../tests/helpers/store';
+import { clearExchangeRateCache } from '../../hooks/useExchangeRates';
+import { useAuthStore } from '../../store/authStore';
+import { useSettingsStore } from '../../store/settingsStore';
+import { useTripStore } from '../../store/tripStore';
+import CostsPanel from './CostsPanel';
+import { resetFreezeAttempts } from './useFreezeMissingRates';
+
+const tripMembers = [
+  { id: 1, username: 'alice', avatar_url: null },
+  { id: 2, username: 'bob', avatar_url: null },
+];
+
+// Alice signed in on an AUD trip whose browser holds an AUD quote: the setup this case
+// ran under beside the bills the server cannot convert in CostsPanel.test.tsx.
+function seedAudTrip() {
+  resetAllStores();
+  seedStore(useAuthStore, { user: buildUser({ id: 1, username: 'alice' }), isAuthenticated: true });
+  seedStore(useSettingsStore, { settings: { ...useSettingsStore.getState().settings, default_currency: 'AUD' } });
+  seedStore(useTripStore, { trip: buildTrip({ id: 1, currency: 'AUD' }) });
+  clearExchangeRateCache();
+  resetFreezeAttempts();
+  localStorage.setItem('trek_fx_AUD', JSON.stringify({ rates: { AUD: 1, VND: 18241.3, EUR: 0.61 }, ts: Date.now() }));
+}
+
+describe('CostsPanel: someone who left the trip (#2604)', () => {
+  beforeEach(seedAudTrip);
+  afterEach(clearExchangeRateCache);
+
+  it('FE-W5COSTS-097: someone who left the trip is named and keeps their balance in the list (#2604)', async () => {
+    // Carol was removed from the trip; her payer row stays on the expense and the
+    // server still nets her into the balances.
+    const item = {
+      ...buildBudgetItem({ trip_id: 1, category: 'food', name: 'Boat' }),
+      total_price: 90,
+      payers: [{ user_id: 3, amount: 90, username: 'carol' }],
+      members: [
+        { user_id: 1, paid: 0, amount: null, username: 'alice' },
+        { user_id: 2, paid: 0, amount: null, username: 'bob' },
+        { user_id: 3, paid: 0, amount: null, username: 'carol' },
+      ],
+    };
+    server.use(
+      http.get('/api/trips/1/budget', () => HttpResponse.json({ items: [item] })),
+      http.get('/api/trips/1/budget/settlement', () =>
+        HttpResponse.json({
+          balances: [
+            { user_id: 1, username: 'alice', avatar_url: null, balance: -30 },
+            { user_id: 2, username: 'bob', avatar_url: null, balance: -30 },
+            { user_id: 3, username: 'carol', avatar_url: null, balance: 60 },
+          ],
+          flows: [],
+          settlements: [],
+        })
+      )
+    );
+    render(<CostsPanel tripId={1} tripMembers={tripMembers} />);
+
+    await screen.findByText('Boat');
+    await waitFor(() => expect(screen.getAllByText('carol').length).toBeGreaterThan(0));
+    expect(screen.queryByText('?')).not.toBeInTheDocument();
+  });
+});
diff --git a/client/src/components/Budget/CostsPanel.summary.test.tsx b/client/src/components/Budget/CostsPanel.summary.test.tsx
index eba1d89cd..c2cd31250 100644
--- a/client/src/components/Budget/CostsPanel.summary.test.tsx
+++ b/client/src/components/Budget/CostsPanel.summary.test.tsx
@@ -60,7 +60,8 @@ describe('CostsPanel: summary footers and won amounts (#2604)', () => {
     mount([owedByBob()], {
       flows: [{ from: { user_id: 2, username: 'bob' }, to: { user_id: 1, username: 'alice' }, amount: 20 }],
     });
-    await screen.findByText('Museum');
+    // The flow comes with the settlement, which can arrive after the expense.
+    await screen.findByRole('button', { name: /^Settle: bob → you/ });
     expect(screen.getByRole('region', { name: 'Outstanding amount' })).not.toHaveTextContent("You're all settled up");
   });
 
@@ -136,7 +137,7 @@ describe('CostsPanel: summary footers and won amounts (#2604)', () => {
       flows: [{ from: { user_id: 2, username: 'bob' }, to: { user_id: 1, username: 'alice' }, amount: 20 }],
     });
     await screen.findByText('Museum');
-    expect(screen.getByRole('button', { name: /^Settle: bob → you, 20,00\s€$/ })).toBeInTheDocument();
+    expect(await screen.findByRole('button', { name: /^Settle: bob → you, 20,00\s€$/ })).toBeInTheDocument();
     expect(screen.getAllByText('bob → you').length).toBeGreaterThan(0);
   });
 });
diff --git a/client/src/components/Budget/CostsPanel.test.tsx b/client/src/components/Budget/CostsPanel.test.tsx
index e727b3115..6a7d8f2d4 100644
--- a/client/src/components/Budget/CostsPanel.test.tsx
+++ b/client/src/components/Budget/CostsPanel.test.tsx
@@ -1094,102 +1094,12 @@ describe('CostsPanel — settle up', () => {
 
     await screen.findByText('You owe')
     const card = screen.getByRole('region', { name: 'You owe' }) as HTMLElement
-    expect(within(card).getByText('To')).toBeInTheDocument()
+    expect(await within(card).findByText('To')).toBeInTheDocument()
     expect(within(card).getByText('bob')).toBeInTheDocument()
     expect(screen.getByText('Nothing owed to you')).toBeInTheDocument()
   })
 })
 
-describe('CostsPanel — filtering the ledger', () => {
-  beforeEach(seedAlice)
-
-  const payment: Payment = { id: 7, from_user_id: 2, to_user_id: 1, amount: 30, created_at: '2025-06-16 10:00:00' }
-
-  it('FE-W5COSTS-014: "Paid by me" keeps only the expenses I fronted', async () => {
-    mount([dinner(), taxi()], { settlements: [payment] })
-
-    await screen.findByText('Taxi')
-    fireEvent.click(screen.getByRole('button', { name: 'Filter' }))
-    fireEvent.click(screen.getByRole('button', { name: 'Paid by me' }))
-
-    expect(screen.getByText('Dinner')).toBeInTheDocument()
-    expect(screen.queryByText('Taxi')).not.toBeInTheDocument()
-    // A transfer I'm part of stays visible under "mine".
-    expect(screen.getByText('Payment')).toBeInTheDocument()
-  })
-
-  it('FE-W5COSTS-015: "I\'m owed" keeps the expenses I am net positive on and drops payments', async () => {
-    mount([dinner(), taxi()], { settlements: [payment] })
-
-    await screen.findByText('Taxi')
-    fireEvent.click(screen.getByRole('button', { name: 'Filter' }))
-    fireEvent.click(screen.getByRole('button', { name: "I'm owed" }))
-
-    expect(screen.getByText('Dinner')).toBeInTheDocument()
-    expect(screen.queryByText('Taxi')).not.toBeInTheDocument()
-    expect(screen.queryByText('Payment')).not.toBeInTheDocument()
-  })
-
-  it('FE-W5COSTS-016: the category filter narrows the ledger and hides payments', async () => {
-    mount([dinner(), taxi()], { settlements: [payment] })
-
-    await screen.findByText('Taxi')
-    fireEvent.click(screen.getByRole('button', { name: 'Filter' }))
-    fireEvent.click(within(screen.getByRole('menu')).getByRole('button', { name: 'Transport' }))
-
-    expect(screen.getByText('Taxi')).toBeInTheDocument()
-    expect(screen.queryByText('Dinner')).not.toBeInTheDocument()
-    expect(screen.queryByText('Payment')).not.toBeInTheDocument()
-  })
-
-  it('FE-W5COSTS-017: picking a single day banners it with that day’s total', async () => {
-    mount([dinner(), taxi()], { settlements: [payment] })
-
-    await screen.findByText('Taxi')
-    fireEvent.click(screen.getByRole('button', { name: 'Filter' }))
-    fireEvent.click(within(screen.getByRole('menu')).getByRole('button', { name: 'Sun, Jun 15' }))
-
-    expect(screen.getByText('Sunday, June 15')).toBeInTheDocument()
-    expect(screen.getByText('1 expense')).toBeInTheDocument()
-    expect(screen.getByText('Dinner')).toBeInTheDocument()
-    expect(screen.queryByText('Taxi')).not.toBeInTheDocument()
-    // The 16th carries the payment, so it is filtered out with the day too.
-    expect(screen.queryByText('Payment')).not.toBeInTheDocument()
-  })
-
-  it('FE-W5COSTS-076: a payment groups by its own settled day, not the day it was recorded', async () => {
-    // Recorded (created_at) on the 16th, but settled on the 15th — the ledger
-    // must follow settled_at, the same way it already follows expense_date over
-    // an expense's own created_at.
-    mount([dinner(), taxi()], { settlements: [{ ...payment, settled_at: '2025-06-15' }] })
-
-    await screen.findByText('Taxi')
-    fireEvent.click(screen.getByRole('button', { name: 'Filter' }))
-    fireEvent.click(within(screen.getByRole('menu')).getByRole('button', { name: 'Sun, Jun 15' }))
-
-    expect(screen.getByText('Dinner')).toBeInTheDocument()
-    expect(screen.queryByText('Taxi')).not.toBeInTheDocument()
-    expect(screen.getByText('Payment')).toBeInTheDocument()
-  })
-
-  it('FE-W5COSTS-018: expenses without a date are grouped under "No date"', async () => {
-    mount([expense({ id: 120, name: 'Souvenirs', category: 'shopping', total_price: 12, expense_date: null })])
-
-    expect(await screen.findByText('No date')).toBeInTheDocument()
-  })
-
-  it('FE-W5COSTS-019: a search with no hits shows the no-match copy', async () => {
-    const user = userEvent.setup()
-    mount([dinner()])
-
-    await screen.findByText('Dinner')
-    await user.type(screen.getByPlaceholderText('Search expenses…'), 'zzz')
-
-    expect(screen.getByText('No expenses match your search.')).toBeInTheDocument()
-    expect(screen.queryByText('Dinner')).not.toBeInTheDocument()
-  })
-})
-
 describe('CostsPanel — expense rows', () => {
   beforeEach(() => {
     seedAlice()
@@ -1222,7 +1132,7 @@ describe('CostsPanel — expense rows', () => {
     await screen.findByText('Diner')
     expect(screen.getByText(/\$100\.00 → 50,00 €/)).toBeInTheDocument()
     // The payer chip and the settlement row are converted the same way.
-    expect(screen.getByText(/\$20\.00 → 10,00 €/)).toBeInTheDocument()
+    expect(await screen.findByText(/\$20\.00 → 10,00 €/)).toBeInTheDocument()
   })
 
   it('FE-W5COSTS-078: a booked rate outlives the live one, for the expense and for the transfer', async () => {
@@ -1242,7 +1152,7 @@ describe('CostsPanel — expense rows', () => {
     expect(screen.getByText(/\$120\.00 → 100,00 €/)).toBeInTheDocument()
     expect(screen.queryByText(/60,00 €/)).toBeNull()
     // The settled transfer is read back the same way: 24 USD booked at 1.2 is 20 euro.
-    expect(screen.getByText(/\$24\.00 → 20,00 €/)).toBeInTheDocument()
+    expect(await screen.findByText(/\$24\.00 → 20,00 €/)).toBeInTheDocument()
   })
 
   it('FE-W5COSTS-022: deleting an expense removes it, and a failure is reported', async () => {
@@ -2527,7 +2437,7 @@ describe('CostsPanel: a bill entered in the display currency (#2525)', () => {
     })
 
     await screen.findByText('Aparthotel Silver')
-    expect(screen.getByText(/\$400\.88 → 342,63\s€$/)).toBeInTheDocument()
+    expect(await screen.findByText(/\$400\.88 → 342,63\s€$/)).toBeInTheDocument()
     // The hotel's split chips can carry the same figure, so look past them to the payment.
     const outsideChips = (text: string) => screen.queryAllByText(text).filter(el => !el.closest('[data-testid="split-chip"]'))
     expect(outsideChips('$395.77')).toHaveLength(1)
@@ -2777,33 +2687,4 @@ describe('CostsPanel: a bill the server cannot convert', () => {
     // currency when it has no quote of its own.
     expect(asked.every(a => a.base === 'IRR' && a.baseRate === null)).toBe(true)
   })
-
-  it('FE-W5COSTS-097: someone who left the trip is named and keeps their balance in the list (#2604)', async () => {
-    // Carol was removed from the trip; her payer row stays on the expense and the
-    // server still nets her into the balances.
-    const item = {
-      ...buildBudgetItem({ trip_id: 1, category: 'food', name: 'Boat' }), total_price: 90,
-      payers: [{ user_id: 3, amount: 90, username: 'carol' }],
-      members: [{ user_id: 1, paid: 0, amount: null, username: 'alice' }, { user_id: 2, paid: 0, amount: null, username: 'bob' }, { user_id: 3, paid: 0, amount: null, username: 'carol' }],
-    }
-    server.use(
-      http.get('/api/trips/1/budget', () => HttpResponse.json({ items: [item] })),
-      http.get('/api/trips/1/budget/settlement', () =>
-        HttpResponse.json({
-          balances: [
-            { user_id: 1, username: 'alice', avatar_url: null, balance: -30 },
-            { user_id: 2, username: 'bob', avatar_url: null, balance: -30 },
-            { user_id: 3, username: 'carol', avatar_url: null, balance: 60 },
-          ],
-          flows: [],
-          settlements: [],
-        })
-      ),
-    )
-    render(<CostsPanel tripId={1} tripMembers={tripMembers} />)
-
-    await screen.findByText('Boat')
-    await waitFor(() => expect(screen.getAllByText('carol').length).toBeGreaterThan(0))
-    expect(screen.queryByText('?')).not.toBeInTheDocument()
-  })
 })