diff --git a/flexmeasures/api/v3_0/assets.py b/flexmeasures/api/v3_0/assets.py
index 14c81edab..abd7a5e53 100644
--- a/flexmeasures/api/v3_0/assets.py
+++ b/flexmeasures/api/v3_0/assets.py
@@ -1,7 +1,10 @@
+from __future__ import annotations
+
 import json
 
 from flask import current_app
 from flask_classful import FlaskView, route
+from flask_login import current_user
 from flask_security import auth_required
 from flask_json import as_json
 from marshmallow import fields
@@ -18,6 +21,8 @@
 from flexmeasures.api.common.schemas.users import AccountIdField
 from flexmeasures.utils.coding_utils import flatten_unique
 from flexmeasures.ui.utils.view_utils import set_session_variables
+from flexmeasures.auth.policy import check_access
+from werkzeug.exceptions import Forbidden, Unauthorized
 
 
 asset_schema = AssetSchema()
@@ -38,21 +43,27 @@ class AssetAPI(FlaskView):
     @route("", methods=["GET"])
     @use_kwargs(
         {
-            "account": AccountIdField(
-                data_key="account_id", load_default=AccountIdField.load_current
+            "account": AccountIdField(data_key="account_id", load_default=None),
+        },
+        location="query",
+    )
+    @use_kwargs(
+        {
+            "all_accessible": fields.Bool(
+                data_key="all_accessible", load_default=False
             ),
         },
         location="query",
     )
-    @permission_required_for_context("read", ctx_arg_name="account")
     @as_json
-    def index(self, account: Account):
-        """List all assets owned by a certain account.
+    def index(self, account: Account | None, all_accessible: bool):
+        """List all assets owned or accessible by a certain account.
 
         .. :quickref: Asset; Download asset list
 
         This endpoint returns all accessible assets for the account of the user.
         The `account_id` query parameter can be used to list assets from a different account.
+        The `all_accessible` query parameter can be used to list all the assets accessible by the requesting user. Defaults to `false`.
 
         **Example response**
 
@@ -80,7 +91,29 @@ def index(self, account: Account):
         :status 403: INVALID_SENDER
         :status 422: UNPROCESSABLE_ENTITY
         """
-        return assets_schema.dump(account.generic_assets), 200
+
+        if all_accessible:
+            accounts = []
+            for _account in db.session.scalars(select(Account)).all():
+                try:
+                    check_access(_account, "read")
+                    accounts.append(_account)
+                except (Forbidden, Unauthorized):
+                    # re-raise exception if the account is provided
+                    # but the requesting user has no read access to it.
+                    if _account == account:
+                        raise
+        else:
+            if account is None:
+                account = current_user.account
+            check_access(account, "read")
+            accounts = [account]
+
+        assets = []
+        for account in accounts:
+            assets.extend(account.generic_assets)
+
+        return assets_schema.dump(assets), 200
 
     @route("/public", methods=["GET"])
     @as_json
diff --git a/flexmeasures/api/v3_0/users.py b/flexmeasures/api/v3_0/users.py
index 378bf5c31..769512ce4 100644
--- a/flexmeasures/api/v3_0/users.py
+++ b/flexmeasures/api/v3_0/users.py
@@ -1,11 +1,13 @@
 from flask_classful import FlaskView, route
 from marshmallow import fields
 from sqlalchemy.exc import IntegrityError
+from sqlalchemy import select
 from webargs.flaskparser import use_kwargs
 from flask_security import current_user, auth_required
 from flask_security.recoverable import send_reset_password_instructions
 from flask_json import as_json
-from werkzeug.exceptions import Forbidden
+from werkzeug.exceptions import Forbidden, Unauthorized
+from flexmeasures.auth.policy import check_access
 
 from flexmeasures.data.models.audit_log import AuditLog
 from flexmeasures.data.models.user import User as UserModel, Account
@@ -41,22 +43,22 @@ class UserAPI(FlaskView):
     @route("", methods=["GET"])
     @use_kwargs(
         {
-            "account": AccountIdField(
-                data_key="account_id", load_default=AccountIdField.load_current
-            ),
+            "account": AccountIdField(data_key="account_id", load_default=None),
             "include_inactive": fields.Bool(load_default=False),
         },
         location="query",
     )
-    @permission_required_for_context("read", ctx_arg_name="account")
     @as_json
     def index(self, account: Account, include_inactive: bool = False):
-        """API endpoint to list all users of an account.
+        """API endpoint to list all users.
+
 
         .. :quickref: User; Download user list
 
         This endpoint returns all accessible users.
         By default, only active users are returned.
+        The `account_id` query parameter can be used to filter the users of
+        a given account.
         The `include_inactive` query parameter can be used to also fetch
         inactive users.
         Accessible users are users in the same account as the current user.
@@ -89,7 +91,25 @@ def index(self, account: Account, include_inactive: bool = False):
         :status 403: INVALID_SENDER
         :status 422: UNPROCESSABLE_ENTITY
         """
-        users = get_users(account_name=account.name, only_active=not include_inactive)
+
+        if account is not None:
+            check_access(account, "read")
+            accounts = [account]
+        else:
+            accounts = []
+            for account in db.session.scalars(select(Account)).all():
+                try:
+                    check_access(account, "read")
+                    accounts.append(account)
+                except (Forbidden, Unauthorized):
+                    pass
+
+        users = []
+        for account in accounts:
+            users += get_users(
+                account_name=account.name,
+                only_active=not include_inactive,
+            )
         return users_schema.dump(users), 200
 
     @route("/<id>")
diff --git a/flexmeasures/data/schemas/generic_assets.py b/flexmeasures/data/schemas/generic_assets.py
index 745020556..8306bb30d 100644
--- a/flexmeasures/data/schemas/generic_assets.py
+++ b/flexmeasures/data/schemas/generic_assets.py
@@ -44,7 +44,7 @@ class GenericAssetSchema(ma.SQLAlchemySchema):
     generic_asset_type_id = fields.Integer(required=True)
     attributes = JSON(required=False)
     parent_asset_id = fields.Int(required=False, allow_none=True)
-    child_assets = ma.Nested("GenericAssetSchema", many=True, dumb_only=True)
+    child_assets = ma.Nested("GenericAssetSchema", many=True, dump_only=True)
 
     class Meta:
         model = GenericAsset
diff --git a/flexmeasures/ui/crud/assets.py b/flexmeasures/ui/crud/assets.py
index 64e50bbb2..a4dd76abd 100644
--- a/flexmeasures/ui/crud/assets.py
+++ b/flexmeasures/ui/crud/assets.py
@@ -214,6 +214,26 @@ def get_assets_by_account(account_id: int | str | None) -> list[GenericAsset]:
     ]
 
 
+def get_all_assets() -> list[GenericAsset]:
+    get_assets_response = (
+        InternalApi()
+        .get(url_for("AssetAPI:index"), query={"all_accessible": True})
+        .json()
+    )
+    get_assets_response_public = InternalApi().get(url_for("AssetAPI:public")).json()
+
+    assets = []
+    if isinstance(get_assets_response, list):
+        assets.extend(get_assets_response)
+
+    if isinstance(get_assets_response_public, list):
+        assets.extend(get_assets_response_public)
+
+    asset_ids_filter = [GenericAsset.id.in_(ad["id"] for ad in assets)]
+
+    return db.session.scalars(select(GenericAsset).where(*asset_ids_filter)).all()
+
+
 class AssetCrudUI(FlaskView):
     """
     These views help us offer a Jinja2-based UI.
@@ -231,14 +251,7 @@ def index(self, msg=""):
 
         List the user's assets. For admins, list across all accounts.
         """
-        assets = []
-
-        if user_has_admin_access(current_user, "read"):
-            for account in db.session.scalars(select(Account)).all():
-                assets += get_assets_by_account(account.id)
-            assets += get_assets_by_account(account_id=None)
-        else:
-            assets = get_assets_by_account(current_user.account_id)
+        assets = get_all_assets()
 
         return render_flexmeasures_template(
             "crud/assets.html",
diff --git a/flexmeasures/ui/crud/users.py b/flexmeasures/ui/crud/users.py
index acc3c720b..9da810c71 100644
--- a/flexmeasures/ui/crud/users.py
+++ b/flexmeasures/ui/crud/users.py
@@ -4,7 +4,6 @@
 
 from flask import request, url_for
 from flask_classful import FlaskView
-from flask_login import current_user
 from flask_security import login_required
 from flask_wtf import FlaskForm
 from wtforms import StringField, FloatField, DateTimeField, BooleanField
@@ -92,6 +91,20 @@ def get_users_by_account(
     return users
 
 
+def get_all_users(include_inactive: bool = False) -> list[User]:
+    get_users_response = InternalApi().get(
+        url_for(
+            "UserAPI:index",
+            include_inactive=include_inactive,
+        )
+    )
+    users = [
+        process_internal_api_response(user, make_obj=True)
+        for user in get_users_response.json()
+    ]
+    return users
+
+
 class UserCrudUI(FlaskView):
     route_base = "/users"
     trailing_slash = False
@@ -100,15 +113,8 @@ class UserCrudUI(FlaskView):
     def index(self):
         """/users"""
         include_inactive = request.args.get("include_inactive", "0") != "0"
-        users = []
-        if current_user.has_role(ADMIN_ROLE) or current_user.has_role(
-            ADMIN_READER_ROLE
-        ):
-            accounts = db.session.scalars(select(Account)).all()
-        else:
-            accounts = [current_user.account]
-        for account in accounts:
-            users += get_users_by_account(account.id, include_inactive)
+        users = get_all_users(include_inactive)
+
         return render_flexmeasures_template(
             "crud/users.html", users=users, include_inactive=include_inactive
         )
diff --git a/flexmeasures/ui/tests/conftest.py b/flexmeasures/ui/tests/conftest.py
index d2b78f811..0a3f080e6 100644
--- a/flexmeasures/ui/tests/conftest.py
+++ b/flexmeasures/ui/tests/conftest.py
@@ -2,6 +2,7 @@
 
 from flexmeasures.data.services.users import create_user
 from flexmeasures.ui.tests.utils import login, logout
+from flexmeasures import Asset
 
 
 @pytest.fixture(scope="function")
@@ -41,3 +42,21 @@ def setup_ui_test_data(
         account_name=setup_accounts["Prosumer"].name,
         user_roles=dict(name="admin", description="A site admin."),
     )
+
+
+@pytest.fixture
+def assets_prosumer(db, setup_accounts, setup_generic_asset_types):
+    assets = []
+    for name in ["TestAsset", "TestAsset2"]:
+        asset = Asset(
+            name=name,
+            generic_asset_type=setup_generic_asset_types["battery"],
+            owner=setup_accounts["Prosumer"],
+            latitude=70.4,
+            longitude=30.9,
+        )
+        assets.append(asset)
+
+    db.session.add_all(assets)
+
+    return assets
diff --git a/flexmeasures/ui/tests/test_asset_crud.py b/flexmeasures/ui/tests/test_asset_crud.py
index 2e2c8aa3f..7d7446848 100644
--- a/flexmeasures/ui/tests/test_asset_crud.py
+++ b/flexmeasures/ui/tests/test_asset_crud.py
@@ -16,28 +16,25 @@
 
 
 def test_assets_page_empty(db, client, requests_mock, as_prosumer_user1):
-    requests_mock.get(f"{api_path_assets}?account_id=1", status_code=200, json={})
-    requests_mock.get(f"{api_path_assets}/public", status_code=200, json={})
+    requests_mock.get(f"{api_path_assets}", status_code=200, json=[])
+    requests_mock.get(f"{api_path_assets}/public", status_code=200, json=[])
     asset_index = client.get(url_for("AssetCrudUI:index"), follow_redirects=True)
     assert asset_index.status_code == 200
 
 
 def test_get_assets_by_account(db, client, requests_mock, as_prosumer_user1):
     mock_assets = mock_asset_response(multiple=True)
-    requests_mock.get(
-        f"{api_path_assets}?account_id=1", status_code=200, json=mock_assets
-    )
+    requests_mock.get(f"{api_path_assets}", status_code=200, json=mock_assets)
     assert get_assets_by_account(1)[1].name == "TestAsset2"
 
 
 @pytest.mark.parametrize("use_owned_by", [False, True])
 def test_assets_page_nonempty(
-    db, client, requests_mock, as_prosumer_user1, use_owned_by
+    db, client, requests_mock, as_prosumer_user1, use_owned_by, assets_prosumer
 ):
     mock_assets = mock_asset_response(multiple=True)
-    requests_mock.get(
-        f"{api_path_assets}?account_id=1", status_code=200, json=mock_assets
-    )
+    requests_mock.get(f"{api_path_assets}", status_code=200, json=mock_assets)
+    requests_mock.get(f"{api_path_assets}/public", status_code=200, json=[])
     if use_owned_by:
         asset_index = client.get(
             url_for("AssetCrudUI:owned_by", account_id=mock_assets[0]["account_id"])
diff --git a/flexmeasures/ui/tests/test_user_crud.py b/flexmeasures/ui/tests/test_user_crud.py
index 62e075c5c..e3823581c 100644
--- a/flexmeasures/ui/tests/test_user_crud.py
+++ b/flexmeasures/ui/tests/test_user_crud.py
@@ -15,7 +15,7 @@
 
 def test_get_users_by_account(client, requests_mock, as_prosumer_user1):
     requests_mock.get(
-        f"http://localhost//api/v3_0/users?account_id={current_user.account.id}",
+        "http://localhost//api/v3_0/users",
         status_code=200,
         json=mock_user_response(multiple=True),
     )
diff --git a/flexmeasures/ui/tests/test_views.py b/flexmeasures/ui/tests/test_views.py
index c2d13536b..78d218915 100644
--- a/flexmeasures/ui/tests/test_views.py
+++ b/flexmeasures/ui/tests/test_views.py
@@ -21,9 +21,14 @@ def test_dashboard_responds_only_for_logged_in_users(client, as_prosumer_user1):
 
 def test_assets_responds(client, requests_mock, as_prosumer_user1):
     requests_mock.get(
-        "http://localhost//api/v3_0/assets?account_id=1",
+        "http://localhost//api/v3_0/assets",
         status_code=200,
-        json={},
+        json=[],
+    )
+    requests_mock.get(
+        "http://localhost//api/v3_0/assets/public",
+        status_code=200,
+        json=[],
     )
     assets_page = client.get(url_for("AssetCrudUI:index"), follow_redirects=True)
     assert assets_page.status_code == 200
diff --git a/flexmeasures/ui/tests/utils.py b/flexmeasures/ui/tests/utils.py
index c5658198d..6783da896 100644
--- a/flexmeasures/ui/tests/utils.py
+++ b/flexmeasures/ui/tests/utils.py
@@ -20,7 +20,7 @@ def logout(client):
 
 
 def mock_asset_response(
-    asset_id: int = 1,
+    asset_id: int = 2,
     account_id: int = 1,
     as_list: bool = True,
     multiple: bool = False,
@@ -38,6 +38,7 @@ def mock_asset_response(
         if multiple:
             asset2 = copy.deepcopy(asset)
             asset2["name"] = "TestAsset2"
+            asset2["id"] += 1
             asset_list.append(asset2)
         return asset_list
     return asset