diff --git a/tests/backoffice/test_merchant_accounts.py b/tests/backoffice/test_merchant_accounts.py
index c88b1431..6c7a742d 100644
--- a/tests/backoffice/test_merchant_accounts.py
+++ b/tests/backoffice/test_merchant_accounts.py
@@ -5,15 +5,18 @@
 import secrets
 
 from utils import MISSING_ID, reach
-from utils.environment import create_client
+from utils.environment import create_client, delete_merchant_account
 
 
-def test_crud_with_partial_update(merchant):
+def test_crud_with_partial_update(merchant, request):
     # Merchant-account operations are account-level, not merchant-scoped, so
     # drive them with an unscoped (admin) client.
     sdk = create_client(merchant.private_key)
     account_id = secrets.token_hex(8)
 
+    request.addfinalizer(
+        lambda: delete_merchant_account(merchant.private_key, account_id)
+    )
     created = sdk.merchant_accounts.create(id=account_id, display_name="Original")
     assert created.id == account_id
 
diff --git a/tests/conftest.py b/tests/conftest.py
index a7e68b1e..0f6bec8c 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -7,6 +7,7 @@
 
 import os
 import sys
+from typing import Iterator
 
 import pytest
 
@@ -17,10 +18,12 @@
 sys.path.insert(0, os.path.dirname(__file__))
 
 # pylint: disable=wrong-import-position
-from utils.environment import setup_merchant
+from utils.environment import delete_merchant_account, setup_merchant
 from utils.merchant import TestMerchant
 
 
 @pytest.fixture(scope="module", name="merchant")
-def merchant_fixture() -> TestMerchant:
-    return setup_merchant()
+def merchant_fixture() -> Iterator[TestMerchant]:
+    merchant = setup_merchant()
+    yield merchant
+    delete_merchant_account(merchant.private_key, merchant.merchant_account_id)
diff --git a/tests/utils/environment.py b/tests/utils/environment.py
index 425ef05d..9a355016 100644
--- a/tests/utils/environment.py
+++ b/tests/utils/environment.py
@@ -57,6 +57,29 @@ def create_client(private_key: str, merchant_account_id: Optional[str] = None) -
     )
 
 
+def delete_merchant_account(private_key: str, merchant_account_id: str) -> None:
+    """Delete a merchant account a suite created; log and carry on if it fails.
+
+    The delete endpoint is not in the public spec, so it is called directly.
+    """
+    try:
+        response = httpx.delete(
+            f"{API_BASE_URL}/merchant-accounts/{merchant_account_id}",
+            headers={"Authorization": f"Bearer {auth.get_token(private_key)}"},
+            timeout=httpx.Timeout(30.0, connect=10.0),
+        )
+        if response.status_code not in (204, 404):
+            _logger.warning(
+                "Failed to delete merchant account %s: HTTP %s",
+                merchant_account_id,
+                response.status_code,
+            )
+    except Exception:  # pylint: disable=broad-exception-caught
+        _logger.warning(
+            "Failed to delete merchant account %s", merchant_account_id, exc_info=True
+        )
+
+
 def setup_merchant() -> TestMerchant:
     """Provision an isolated merchant account + mock-card service.
 
@@ -66,19 +89,22 @@ def setup_merchant() -> TestMerchant:
     admin = create_client(private_key)
 
     merchant_account_id = secrets.token_hex(8)
-    admin.merchant_accounts.create(
-        id=merchant_account_id, display_name=merchant_account_id
-    )
-
     client = create_client(private_key, merchant_account_id)
-    client.payment_services.create(
-        display_name="Payment service",
-        payment_service_definition_id="mock-card",
-        fields=[{"key": "merchant_id", "value": "test"}],
-        accepted_currencies=["USD"],
-        accepted_countries=["US"],
-        active=True,
-    )
+    try:
+        admin.merchant_accounts.create(
+            id=merchant_account_id, display_name=merchant_account_id
+        )
+        client.payment_services.create(
+            display_name="Payment service",
+            payment_service_definition_id="mock-card",
+            fields=[{"key": "merchant_id", "value": "test"}],
+            accepted_currencies=["USD"],
+            accepted_countries=["US"],
+            active=True,
+        )
+    except Exception:
+        delete_merchant_account(private_key, merchant_account_id)
+        raise
 
     return TestMerchant(
         client=client,