diff --git a/csaxs_bec/bec_ipython_client/plugins/LamNI/lamni.py b/csaxs_bec/bec_ipython_client/plugins/LamNI/lamni.py
index 93a4e05..e495ec3 100644
--- a/csaxs_bec/bec_ipython_client/plugins/LamNI/lamni.py
+++ b/csaxs_bec/bec_ipython_client/plugins/LamNI/lamni.py
@@ -238,10 +238,77 @@ class LamNI(TomoQueueMixin, LamNIAlignmentMixin, LamNIOpticsMixin, LamniGuiTools
         )
         self._webpage_gen.start()
 
+        self._maybe_reset_params_on_account_change()
+
     def set_web_password(self, password: str) -> None:
         """Set the web password for the current BEC account."""
         self._webpage_gen.set_web_password(password)
 
+    def _maybe_reset_params_on_account_change(self) -> None:
+        """Offer a tomo-parameter reset when the active account has changed.
+
+        Called at BEC session start. The account for which defaults were last
+        applied is stored in the global var ``defaults_applied_for_account`` so
+        it survives client restarts. Only a genuine change of account triggers
+        the (interactive) reset; the same account is a silent no-op, so
+        restarting a client within the same experiment never disturbs tuned
+        parameters. Mirrors Flomni._maybe_reset_params_on_account_change()
+        exactly.
+        """
+        bec = builtins.__dict__.get("bec")
+        try:
+            account = bec.active_account
+        except Exception as exc:
+            print(f"account-change check skipped: cannot read active_account: {exc}")
+            return
+        if not account:
+            return
+
+        last_account = self.client.get_global_var("defaults_applied_for_account")
+        if account == last_account:
+            return
+
+        if self.OMNYTools.yesno(
+            f"New account '{account}' detected (previous: '{last_account}').\n"
+            "Reset tomo parameters to defaults for the new experiment?",
+            "y",
+        ):
+            self._set_default_tomo_params()
+            print(f"Tomo parameters reset to defaults for account '{account}'.")
+        self.client.set_global_var("defaults_applied_for_account", account)
+
+    def _set_default_tomo_params(self) -> None:
+        """Write all tomo scan parameters back to their default values.
+
+        These are the same baseline values used as the getter fallbacks. Per-
+        sample alignment state (corrections, alignment offsets) is
+        deliberately not reset here, as it is overwritten by the next
+        alignment anyway. Mirrors Flomni._set_default_tomo_params(), adapted
+        to lamni's own param names -- no fovx/fovy/stitch_x/stitch_y/
+        tomo_angle_range/single_point_random_shift_max; lamni has
+        tomo_circfov/lamni_stitch_x/y/lamni_piezo_range_x/y instead, is
+        always 360 degrees, and has no single-point acquisition mode.
+        """
+        self.tomo_shellstep = 1
+        self.tomo_countingtime = 0.1
+        self.manual_shift_x = 0.0
+        self.manual_shift_y = 0.0
+        self.tomo_circfov = 0.0
+        self.tomo_type = 1
+        self.corridor_size = -1
+        self.lamni_stitch_x = 0
+        self.lamni_stitch_y = 0
+        self.ptycho_reconstruct_foldername = "ptycho_reconstruct"
+        self.tomo_angle_stepsize = 10.0
+        self.golden_max_number_of_projections = 1000.0
+        self.tomo_stitch_overlap = 0.2
+        self.golden_projections_at_0_deg_for_damage_estimation = 0
+        self.zero_deg_reference_at_each_subtomo = False
+        self.golden_ratio_bunch_size = 20
+        self.frames_per_trigger = 1
+        self.lamni_piezo_range_x = 20
+        self.lamni_piezo_range_y = 20
+
     # ------------------------------------------------------------------
     # Special angles
     # ------------------------------------------------------------------
diff --git a/tests/tests_bec_ipython_client/test_lamni_account_change_reset.py b/tests/tests_bec_ipython_client/test_lamni_account_change_reset.py
new file mode 100644
index 0000000..d879831
--- /dev/null
+++ b/tests/tests_bec_ipython_client/test_lamni_account_change_reset.py
@@ -0,0 +1,127 @@
+"""Tests for lamni's tomo-parameter reset offer on experiment-account
+change, ported from flomni (see csaxs_bec/bec_ipython_client/plugins/LamNI/
+AI_docs/FLOMNI_LAMNI_FEATURE_GAPS_2026-07.md, item 2).
+
+Uses a bare LamNI instance (bypassing __init__'s heavy side effects), same
+pattern as test_lamni_tomo_queue.py/test_tomo_queue_reacquire.py.
+"""
+
+import builtins
+import types
+
+import csaxs_bec.bec_ipython_client.plugins.LamNI.lamni as lamni_module
+from csaxs_bec.bec_ipython_client.plugins.LamNI.lamni import LamNI, _ProgressProxy
+
+
+class FakeClient:
+    """Minimal in-memory stand-in for BEC's global-var store."""
+
+    def __init__(self):
+        self._vars = {}
+
+    def get_global_var(self, key):
+        return self._vars.get(key)
+
+    def set_global_var(self, key, value):
+        self._vars[key] = value
+
+
+class FakeOMNYTools:
+    def __init__(self, answer=True):
+        self.answer = answer
+        self.prompts = []
+
+    def yesno(self, prompt, default):
+        self.prompts.append(prompt)
+        return self.answer
+
+
+class _FakeRtx:
+    user_parameter = {"large_range_scan": True}
+
+
+class _FakeDev:
+    rtx = _FakeRtx()
+
+    def __contains__(self, name):
+        return hasattr(self, name)
+
+    def __getitem__(self, name):
+        return getattr(self, name)
+
+
+def make_lamni(answer=True):
+    lamni_module.dev = _FakeDev()
+    obj = object.__new__(LamNI)
+    obj.client = FakeClient()
+    obj._progress_proxy = _ProgressProxy(obj.client)
+    obj.OMNYTools = FakeOMNYTools(answer=answer)
+    obj.reconstructor = types.SimpleNamespace(folder_name=None)
+    return obj
+
+
+def test_skips_silently_when_no_active_account():
+    lamni = make_lamni()
+    builtins.__dict__["bec"] = type("Bec", (), {"active_account": ""})()
+
+    lamni._maybe_reset_params_on_account_change()
+
+    assert lamni.client.get_global_var("defaults_applied_for_account") is None
+    assert lamni.OMNYTools.prompts == []
+
+
+def test_skips_silently_on_same_account():
+    lamni = make_lamni()
+    lamni.client.set_global_var("defaults_applied_for_account", "e12345")
+    builtins.__dict__["bec"] = type("Bec", (), {"active_account": "e12345"})()
+    lamni.tomo_shellstep = 99.0
+
+    lamni._maybe_reset_params_on_account_change()
+
+    assert lamni.OMNYTools.prompts == []
+    assert lamni.tomo_shellstep == 99.0
+
+
+def test_prompts_and_resets_on_new_account_when_confirmed():
+    lamni = make_lamni(answer=True)
+    lamni.client.set_global_var("defaults_applied_for_account", "e11111")
+    lamni.tomo_shellstep = 99.0
+    lamni.tomo_circfov = 123.0
+    builtins.__dict__["bec"] = type("Bec", (), {"active_account": "e22222"})()
+
+    lamni._maybe_reset_params_on_account_change()
+
+    assert len(lamni.OMNYTools.prompts) == 1
+    assert "e22222" in lamni.OMNYTools.prompts[0]
+    assert "e11111" in lamni.OMNYTools.prompts[0]
+    assert lamni.tomo_shellstep == 1
+    assert lamni.tomo_circfov == 0.0
+    assert lamni.client.get_global_var("defaults_applied_for_account") == "e22222"
+
+
+def test_records_account_without_resetting_when_declined():
+    lamni = make_lamni(answer=False)
+    lamni.client.set_global_var("defaults_applied_for_account", "e11111")
+    lamni.tomo_shellstep = 99.0
+    builtins.__dict__["bec"] = type("Bec", (), {"active_account": "e22222"})()
+
+    lamni._maybe_reset_params_on_account_change()
+
+    assert lamni.tomo_shellstep == 99.0
+    assert lamni.client.get_global_var("defaults_applied_for_account") == "e22222"
+
+
+def test_set_default_tomo_params_matches_getter_fallbacks():
+    """Every value _set_default_tomo_params() writes must match the property
+    getter's own None-fallback -- otherwise "reset to defaults" and "never
+    configured" would silently disagree."""
+    lamni = make_lamni()
+
+    lamni._set_default_tomo_params()
+
+    for name in LamNI._TOMO_SCAN_PARAM_NAMES:
+        if name == "at_each_angle_hook":
+            continue  # deliberately not touched by a reset, mirrors flomni
+        fresh = object.__new__(LamNI)
+        fresh.client = FakeClient()
+        assert getattr(lamni, name) == getattr(fresh, name), name