diff --git a/supabase/migrations/20260418033458_e7c5d0e1-b39f-4cee-8bf0-099a35fb142d.sql b/supabase/migrations/20260418033458_e7c5d0e1-b39f-4cee-8bf0-099a35fb142d.sql
new file mode 100644
index 0000000..e6277f7
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+++ b/supabase/migrations/20260418033458_e7c5d0e1-b39f-4cee-8bf0-099a35fb142d.sql
@@ -0,0 +1,95 @@
+-- Remove clients & contacts created in the last 24 hours (the bulk-imported batch).
+-- Cascading clean-up of dependent rows that don't have ON DELETE CASCADE.
+
+-- 1. Identify target sets
+WITH del_clients AS (
+  SELECT id FROM public.clients WHERE created_at >= now() - interval '24 hours'
+),
+del_contacts AS (
+  SELECT id FROM public.contacts WHERE created_at >= now() - interval '24 hours'
+),
+-- Homeowners belonging to those clients
+del_homeowners AS (
+  SELECT id FROM public.homeowners WHERE client_id IN (SELECT id FROM del_clients)
+),
+-- Cases belonging to those clients
+del_cases AS (
+  SELECT id FROM public.cases WHERE client_id IN (SELECT id FROM del_clients)
+),
+-- Collections under those cases / homeowners
+del_collections AS (
+  SELECT id FROM public.collections
+  WHERE case_id IN (SELECT id FROM del_cases)
+     OR homeowner_id IN (SELECT id FROM del_homeowners)
+),
+-- Invoices belonging to those clients / cases
+del_invoices AS (
+  SELECT id FROM public.invoices
+  WHERE client_id IN (SELECT id FROM del_clients)
+     OR case_id IN (SELECT id FROM del_cases)
+)
+-- Materialise into temp tables for reuse across statements
+SELECT id INTO TEMP TABLE _del_clients FROM del_clients;
+WITH t AS (SELECT id FROM public.contacts WHERE created_at >= now() - interval '24 hours')
+SELECT id INTO TEMP TABLE _del_contacts FROM t;
+WITH t AS (SELECT id FROM public.homeowners WHERE client_id IN (SELECT id FROM _del_clients))
+SELECT id INTO TEMP TABLE _del_homeowners FROM t;
+WITH t AS (SELECT id FROM public.cases WHERE client_id IN (SELECT id FROM _del_clients))
+SELECT id INTO TEMP TABLE _del_cases FROM t;
+WITH t AS (
+  SELECT id FROM public.collections
+  WHERE case_id IN (SELECT id FROM _del_cases)
+     OR homeowner_id IN (SELECT id FROM _del_homeowners)
+)
+SELECT id INTO TEMP TABLE _del_collections FROM t;
+WITH t AS (
+  SELECT id FROM public.invoices
+  WHERE client_id IN (SELECT id FROM _del_clients)
+     OR case_id IN (SELECT id FROM _del_cases)
+)
+SELECT id INTO TEMP TABLE _del_invoices FROM t;
+
+-- 2. Delete dependents bottom-up
+-- Collections sub-data
+DELETE FROM public.payment_plan_installments WHERE plan_id IN (SELECT id FROM public.payment_plans WHERE collection_id IN (SELECT id FROM _del_collections));
+DELETE FROM public.payment_plans WHERE collection_id IN (SELECT id FROM _del_collections);
+DELETE FROM public.collection_payment_allocations WHERE collection_id IN (SELECT id FROM _del_collections);
+DELETE FROM public.collection_ledger_entries WHERE collection_id IN (SELECT id FROM _del_collections);
+DELETE FROM public.collection_tasks WHERE collection_id IN (SELECT id FROM _del_collections);
+DELETE FROM public.collections WHERE id IN (SELECT id FROM _del_collections);
+
+-- Invoice sub-data
+DELETE FROM public.invoice_payments WHERE invoice_id IN (SELECT id FROM _del_invoices);
+DELETE FROM public.invoice_line_items WHERE invoice_id IN (SELECT id FROM _del_invoices);
+UPDATE public.expenses SET invoice_id = NULL WHERE invoice_id IN (SELECT id FROM _del_invoices);
+DELETE FROM public.invoices WHERE id IN (SELECT id FROM _del_invoices);
+
+-- Case sub-data
+DELETE FROM public.expenses WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.call_logs WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.documents WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.document_folders WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.case_field_values WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.case_contacts WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.status_updates WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.events WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.tasks WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.comments WHERE case_id IN (SELECT id FROM _del_cases);
+DELETE FROM public.cases WHERE id IN (SELECT id FROM _del_cases);
+
+-- Homeowner sub-data
+DELETE FROM public.call_logs WHERE homeowner_id IN (SELECT id FROM _del_homeowners);
+DELETE FROM public.homeowners WHERE id IN (SELECT id FROM _del_homeowners);
+
+-- Contact sub-data
+DELETE FROM public.case_contacts WHERE contact_id IN (SELECT id FROM _del_contacts);
+DELETE FROM public.client_contacts WHERE contact_id IN (SELECT id FROM _del_contacts);
+DELETE FROM public.call_logs WHERE contact_id IN (SELECT id FROM _del_contacts);
+DELETE FROM public.contacts WHERE id IN (SELECT id FROM _del_contacts);
+
+-- Client sub-data
+DELETE FROM public.client_contacts WHERE client_id IN (SELECT id FROM _del_clients);
+DELETE FROM public.events WHERE client_id IN (SELECT id FROM _del_clients);
+DELETE FROM public.clients WHERE id IN (SELECT id FROM _del_clients);
+
+DROP TABLE _del_clients, _del_contacts, _del_homeowners, _del_cases, _del_collections, _del_invoices;
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