diff --git a/pyproject.toml b/pyproject.toml
index 7bc3ec19..f40b295c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -61,6 +61,13 @@ extend-select = [
     "UP035",
     # Missing function argument type-annotation
     "ANN001",
+    "ANN002",
+    "ANN003",
+    "ANN201",
+    "ANN202",
+    "ANN204",
+    "ANN205",
+    "ANN206",
     # Using except without specifying an exception type to catch
     "BLE001",
 ]
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 9d866a74..4715a7ec 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -48,7 +48,7 @@
         realisation_to_srf,
     ],
 )
-def test_invocation_of_script(script: Callable):
+def test_invocation_of_script(script: Callable) -> None:
     """Basic check that the scripts can be invoked."""
     runner = CliRunner()
     result = runner.invoke(script.app, ["--help"])
diff --git a/tests/test_log_utils.py b/tests/test_log_utils.py
index 5d599ae9..db385373 100644
--- a/tests/test_log_utils.py
+++ b/tests/test_log_utils.py
@@ -11,11 +11,11 @@
 
 
 @log_utils.log_call()
-def foo(a: int, b: int):
+def foo(a: int, b: int) -> int:
     return a + b
 
 
-def test_basic_log():
+def test_basic_log() -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
@@ -35,11 +35,11 @@ def test_basic_log():
 
 
 @log_utils.log_call(exclude_args={"b"})
-def foo_less_b(a: int, b: int):
+def foo_less_b(a: int, b: int) -> int:
     return a + b
 
 
-def test_excluded_log():
+def test_excluded_log() -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
@@ -59,11 +59,11 @@ def test_excluded_log():
 
 
 @log_utils.log_call(action_name="FOOBAR")
-def bar(a: Any):
+def bar(a: Any) -> None:
     pass
 
 
-def test_renamed_bar():
+def test_renamed_bar() -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
@@ -81,11 +81,11 @@ def test_renamed_bar():
 
 
 @log_utils.log_call(include_result=False)
-def baz(a: Any):
+def baz(a: Any) -> int:
     return 1
 
 
-def test_no_result():
+def test_no_result() -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
@@ -104,11 +104,11 @@ def test_no_result():
 
 
 @log_utils.log_call()
-def failing_function():
+def failing_function() -> None:
     raise ValueError("This function should fail!")
 
 
-def test_failing_function():
+def test_failing_function() -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
@@ -122,7 +122,7 @@ def test_failing_function():
     assert "error" in return_log
 
 
-def test_successful_check_call_log(tmp_path: Path):
+def test_successful_check_call_log(tmp_path: Path) -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
@@ -140,7 +140,7 @@ def test_successful_check_call_log(tmp_path: Path):
     assert "stdout" in completion_message and "test.txt" in completion_message["stdout"]
 
 
-def test_failing_check_call_log():
+def test_failing_check_call_log() -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
@@ -156,7 +156,7 @@ def test_failing_check_call_log():
     )
 
 
-def test_repeated_logs():
+def test_repeated_logs() -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
@@ -177,12 +177,12 @@ def test_repeated_logs():
     )
 
 
-def _thread_worker(logger_name: str):
+def _thread_worker(logger_name: str) -> None:
     logger = log_utils.get_logger(logger_name)
     logger.info("Threaded log message")
 
 
-def test_thread_safety():
+def test_thread_safety() -> None:
     log_capture = structlog.testing.LogCapture()
     structlog.configure(processors=[log_capture])
 
diff --git a/tests/test_realisation.py b/tests/test_realisation.py
index e8e5289b..14296d96 100644
--- a/tests/test_realisation.py
+++ b/tests/test_realisation.py
@@ -18,7 +18,7 @@
 from workflow import defaults, realisations
 
 
-def test_bounding_box_example(tmp_path: Path):
+def test_bounding_box_example(tmp_path: Path) -> None:
     domain_parameters = realisations.DomainParameters(
         resolution=0.1,  # a 0.1km resolution
         domain=bounding_box.BoundingBox.from_centroid_bearing_extents(
@@ -60,7 +60,7 @@ def test_bounding_box_example(tmp_path: Path):
     ).all()
 
 
-def test_domain_parameters_properties():
+def test_domain_parameters_properties() -> None:
     domain_parameters = realisations.DomainParameters(
         resolution=0.1,  # a 0.1km resolution
         domain=bounding_box.BoundingBox.from_centroid_bearing_extents(
@@ -78,7 +78,7 @@ def test_domain_parameters_properties():
     assert domain_parameters.nz == 400
 
 
-def test_srf_config_example(tmp_path: Path):
+def test_srf_config_example(tmp_path: Path) -> None:
     domain_parameters = realisations.DomainParameters(
         resolution=0.1,  # a 0.1km resolution
         domain=bounding_box.BoundingBox.from_centroid_bearing_extents(
@@ -124,7 +124,7 @@ def test_srf_config_example(tmp_path: Path):
     assert realisations.SRFConfig.read_from_realisation(realisation_ffp) == srf_config
 
 
-def test_bad_domain_parameters(tmp_path: Path):
+def test_bad_domain_parameters(tmp_path: Path) -> None:
     bad_json = tmp_path / "bad_domain_parameters.json"
     bad_json.write_text(
         json.dumps(
@@ -160,7 +160,7 @@ def test_bad_domain_parameters(tmp_path: Path):
         realisations.DomainParameters.read_from_realisation(bad_json)
 
 
-def test_bad_config_key(tmp_path: Path):
+def test_bad_config_key(tmp_path: Path) -> None:
     bad_json = tmp_path / "bad_domain_parameters.json"
     bad_json.write_text(
         json.dumps(
@@ -196,7 +196,7 @@ def test_bad_config_key(tmp_path: Path):
         realisations.DomainParameters.read_from_realisation(bad_json)
 
 
-def test_metadata(tmp_path: Path):
+def test_metadata(tmp_path: Path) -> None:
     metadata = realisations.RealisationMetadata(
         name="consecutive write test",
         version="1",
@@ -220,7 +220,7 @@ def test_metadata(tmp_path: Path):
     )
 
 
-def test_velocity_model(tmp_path: Path):
+def test_velocity_model(tmp_path: Path) -> None:
     velocity_model = realisations.VelocityModelParameters(
         min_vs=1.0,
         version="2.06",
@@ -257,7 +257,7 @@ def test_velocity_model(tmp_path: Path):
     )
 
 
-def test_rupture_prop_config(tmp_path: Path):
+def test_rupture_prop_config(tmp_path: Path) -> None:
     rup_prop = realisations.RupturePropagationConfig(
         rupture_causality_tree={"A": None, "B": "A", "C": "B"},
         jump_points={
@@ -307,7 +307,7 @@ def test_rupture_prop_config(tmp_path: Path):
     assert rupture_prop_config.hypocentre.tolist() == [0.0, 0.6]
 
 
-def test_rupture_prop_properties():
+def test_rupture_prop_properties() -> None:
     rup_prop = realisations.RupturePropagationConfig(
         rupture_causality_tree={"A": None, "B": "A", "C": "B"},
         jump_points={
@@ -325,7 +325,7 @@ def test_rupture_prop_properties():
     assert rup_prop.initial_fault == "A"
 
 
-def test_hf_config(tmp_path: Path):
+def test_hf_config(tmp_path: Path) -> None:
     test_realisation = tmp_path / "realisation.json"
     test_realisation.write_text("{}")
     hf_config = realisations.HFConfig.read_from_realisation_or_defaults(
@@ -344,7 +344,7 @@ def test_hf_config(tmp_path: Path):
     )
 
 
-def test_emod3d(tmp_path: Path):
+def test_emod3d(tmp_path: Path) -> None:
     test_realisation = tmp_path / "realisation.json"
     test_realisation.write_text("{}")
     emod3d = realisations.EMOD3DParameters.read_from_realisation_or_defaults(
@@ -363,7 +363,7 @@ def test_emod3d(tmp_path: Path):
     )
 
 
-def test_broadband_parameters(tmp_path: Path):
+def test_broadband_parameters(tmp_path: Path) -> None:
     test_realisation = tmp_path / "realisation.json"
     broadband_parameters = realisations.BroadbandParameters(
         flo=0.5, dt=0.005, fmidbot=0.5, fmin=0.25, site_amp_version="2014"
@@ -385,14 +385,14 @@ def test_broadband_parameters(tmp_path: Path):
     )
 
 
-def test_logtrail_init_empty():
+def test_logtrail_init_empty() -> None:
     """Test LogTrail initialization with no log provided."""
     trail = realisations.LogTrail([])
     assert trail.log == []
     assert trail._config_key == "log_trail"
 
 
-def test_logtrail_init_with_log_entries():
+def test_logtrail_init_with_log_entries() -> None:
     """Test LogTrail initialization with a list of LogEntry objects."""
     entry1 = realisations.LogEntry(
         utility="util1", args=["a"], version="1", timestamp=datetime.now()
@@ -404,7 +404,7 @@ def test_logtrail_init_with_log_entries():
     assert trail.log == [entry1, entry2]
 
 
-def test_logtrail_init_with_dicts_post_init():
+def test_logtrail_init_with_dicts_post_init() -> None:
     """Test LogTrail post_init conversion of dicts to LogEntry objects."""
     log_data = [
         {
@@ -431,7 +431,7 @@ def test_logtrail_init_with_dicts_post_init():
     assert trail.log[1].args == ["b"]
 
 
-def test_logtrail_log_entry_method():
+def test_logtrail_log_entry_method() -> None:
     """Test adding an entry using the log_entry method."""
     trail = realisations.LogTrail([])
     trail.log_entry("my_util", ["--flag", "value"])
@@ -442,7 +442,7 @@ def test_logtrail_log_entry_method():
     assert isinstance(trail.log[0].timestamp, datetime)
 
 
-def test_logtrail_to_dict():
+def test_logtrail_to_dict() -> None:
     """Test converting LogTrail to a dictionary."""
     ts = datetime.now()
     entry1 = realisations.LogEntry(
@@ -480,7 +480,7 @@ def test_logtrail_to_dict():
 
 def test_append_log_entry_file_exists_no_key(
     tmp_path: Path,
-):
+) -> None:
     """Test append_log_entry when file exists but lacks the 'log_trail' key."""
     realisation_file = tmp_path / "test_realisation.json"
     # Create a file with unrelated content
@@ -504,7 +504,7 @@ def test_append_log_entry_file_exists_no_key(
     assert data["log_trail"]["log"][0]["utility"] == "script_name.py"
 
 
-def test_seeds():
+def test_seeds() -> None:
     seeds = realisations.Seeds.random_seeds()
     assert all(
         0 <= seed <= 2 ** (struct.Struct("i").size * 8 - 1) - 1
@@ -512,7 +512,7 @@ def test_seeds():
     )
 
 
-def test_velocity_model_1d(tmp_path: Path):
+def test_velocity_model_1d(tmp_path: Path) -> None:
     velocity_model_1d = realisations.VelocityModel1D(
         model=pd.DataFrame(
             {
@@ -564,7 +564,7 @@ def test_velocity_model_1d(tmp_path: Path):
     )
 
 
-def test_intensity_measure_calculation_parameters(tmp_path: Path):
+def test_intensity_measure_calculation_parameters(tmp_path: Path) -> None:
     im_calc_params = realisations.IntensityMeasureCalculationParameters(
         ims=[im_calculation.IM("PGA"), im_calculation.IM("PGV")],
         valid_periods=np.array([0.1, 0.2, 0.3]),
@@ -605,5 +605,5 @@ def test_defaults_are_loadable(
     tmp_path: Path,
     realisation_config: realisations.RealisationConfiguration,
     defaults_version: defaults.DefaultsVersion,
-):
+) -> None:
     realisation_config.read_from_defaults(defaults_version)
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 51936f0b..de823b6f 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -4,14 +4,16 @@
 from workflow import utils
 
 
-def test_get_available_cores_slurm_cpus_on_node():
+def test_get_available_cores_slurm_cpus_on_node() -> None:
     with patch.dict(os.environ, {"SLURM_CPUS_ON_NODE": "4"}):
         assert utils.get_available_cores() == 4
 
-def get_available_cores_slurm_nprocs():
+
+def get_available_cores_slurm_nprocs() -> None:
     with patch.dict(os.environ, {"SLURM_NPROCS": "8"}):
         assert utils.get_available_cores() == 8
 
-def get_available_cores_no_slurm():
+
+def get_available_cores_no_slurm() -> None:
     with patch("multiprocessing.cpu_count", return_value=16):
         assert utils.get_available_cores() == 16
diff --git a/workflow/log_utils.py b/workflow/log_utils.py
index 073735c3..bfde980e 100644
--- a/workflow/log_utils.py
+++ b/workflow/log_utils.py
@@ -84,7 +84,9 @@ def log_call(
 
     def decorator(f: Callable) -> Callable:  # numpydoc ignore=GL08
         @functools.wraps(f)
-        def wrapper(*args, **kwargs):  # numpydoc ignore=GL08
+        def wrapper(
+            *args: list[Any], **kwargs: dict[str, Any]
+        ) -> Any:  # numpydoc ignore=GL08
             nonlocal exclude_args
             signature = inspect.signature(f)
             function_id = str(uuid.uuid4())
diff --git a/workflow/realisations.py b/workflow/realisations.py
index 6a8c7959..d679ea69 100644
--- a/workflow/realisations.py
+++ b/workflow/realisations.py
@@ -243,7 +243,7 @@ class Seeds(RealisationConfiguration):
 
     @classmethod
     def read_from_realisation_or_defaults(
-        cls, realisation_ffp: Path, *args
+        cls, realisation_ffp: Path, *args: list[Any]
     ) -> Self:  # *args is to maintain compat with superclass (remove this and see the error in mypy).
         """Read seeds configuration from a realisation file or generate random seeds if not present.
 
@@ -256,7 +256,7 @@ def read_from_realisation_or_defaults(
         ----------
         realisation_ffp : Path
             The realisation filepath to read from.
-        *args : Any
+        *args : list
             Ignored arguments.
 
         Returns
@@ -315,7 +315,7 @@ class SourceConfig(RealisationConfiguration):
     source_geometries: dict[str, IsSource]
     """Dictionary mapping source names to their definitions."""
 
-    def to_dict(self):
+    def to_dict(self) -> dict[str, Any]:
         """
         Convert the object to a dictionary representation.
 
@@ -522,7 +522,7 @@ class VelocityModel1D(RealisationConfiguration):
 
     model: pd.DataFrame
 
-    def write_velocity_model(self, velocity_model_path: Path):
+    def write_velocity_model(self, velocity_model_path: Path) -> None:
         """Write a 1D velocity model to the specified path.
 
         Parameters
diff --git a/workflow/scripts/bb_sim.py b/workflow/scripts/bb_sim.py
index 689fea2f..3771f648 100644
--- a/workflow/scripts/bb_sim.py
+++ b/workflow/scripts/bb_sim.py
@@ -81,7 +81,7 @@ def bb_simulate_station(
     n2: float,
     station_name: str,
     station: pd.Series,
-):
+) -> None:
     """Simulate broadband seismic for a single station.
 
     Combines the low frequency and high frequency waveforms together
@@ -185,7 +185,7 @@ def combine_hf_and_lf(
         Path, typer.Argument(file_okay=False, exists=True)
     ],
     output_ffp: Annotated[Path, typer.Argument(dir_okay=False, writable=True)],
-):
+) -> None:
     """Combine low-frequency and high-frequency seismic waveforms.
 
     Parameters
diff --git a/workflow/scripts/check_domain.py b/workflow/scripts/check_domain.py
index 6e3e8551..5340ce1e 100644
--- a/workflow/scripts/check_domain.py
+++ b/workflow/scripts/check_domain.py
@@ -47,7 +47,7 @@ def check_domain(
     realisation_ffp: Annotated[Path, typer.Argument()],
     srf_ffp: Annotated[Path, typer.Argument()],
     velocity_model: Annotated[Path, typer.Argument()],
-):
+) -> None:
     """Check an SRF's contents for viability.
 
     Parameters
diff --git a/workflow/scripts/check_srf.py b/workflow/scripts/check_srf.py
index 358cb57d..10de9d94 100644
--- a/workflow/scripts/check_srf.py
+++ b/workflow/scripts/check_srf.py
@@ -54,7 +54,7 @@
 def check_srf(
     realisation_ffp: Annotated[Path, typer.Argument()],
     srf_ffp: Annotated[Path, typer.Argument()],
-):
+) -> None:
     """Check an SRF's contents for viability.
 
     Parameters
diff --git a/workflow/scripts/create_e3d_par.py b/workflow/scripts/create_e3d_par.py
index ed25b693..488f2ad7 100644
--- a/workflow/scripts/create_e3d_par.py
+++ b/workflow/scripts/create_e3d_par.py
@@ -254,7 +254,7 @@ def create_e3d_par(
         "/EMOD3D/tools/emod3d-mpi_v3.0.8"
     ),
     emod3d_version: Annotated[str, typer.Option()] = "3.0.8",
-):
+) -> None:
     """Create EMOD3D parameter file from provided inputs.
 
     Parameters
diff --git a/workflow/scripts/gcmt_auto_simulate.py b/workflow/scripts/gcmt_auto_simulate.py
index c7d366e2..7744dfcc 100755
--- a/workflow/scripts/gcmt_auto_simulate.py
+++ b/workflow/scripts/gcmt_auto_simulate.py
@@ -77,7 +77,7 @@ def get_nz_outline_polygon() -> Polygon:
 def gcmt_auto_simulate(
     gcmt_solutions_url: Annotated[str, typer.Argument()],
     old_gcmt_solutions_path: Annotated[Path, typer.Argument()],
-):
+) -> None:
     """Automatically simulate GCMT solutions that are new, large, and within 30 km of New Zealand.
 
     Parameters
diff --git a/workflow/scripts/gcmt_to_realisation.py b/workflow/scripts/gcmt_to_realisation.py
index e9dc9aaa..994a6fa2 100644
--- a/workflow/scripts/gcmt_to_realisation.py
+++ b/workflow/scripts/gcmt_to_realisation.py
@@ -103,7 +103,7 @@ def gcmt_to_realisation(
     nodal_plane: Annotated[
         NodalPlaneChoice, typer.Option()
     ] = NodalPlaneChoice.MOST_LIKELY,
-):
+) -> None:
     """Generate a realisation from a GCMT solution.
 
     Parameters
diff --git a/workflow/scripts/generate_rupture_propagation.py b/workflow/scripts/generate_rupture_propagation.py
index 49f14795..36617220 100644
--- a/workflow/scripts/generate_rupture_propagation.py
+++ b/workflow/scripts/generate_rupture_propagation.py
@@ -137,7 +137,7 @@ def generate_rupture_propagation(
     ],
     shypo: Annotated[Optional[float], typer.Option(min=0, max=1)] = None,
     dhypo: Annotated[Optional[float], typer.Option(min=0, max=1)] = None,
-):
+) -> None:
     """Generate a likely rupture propagation for a given set of sources.
 
     Parameters
diff --git a/workflow/scripts/generate_stoch.py b/workflow/scripts/generate_stoch.py
index 3704492e..f59e4a97 100644
--- a/workflow/scripts/generate_stoch.py
+++ b/workflow/scripts/generate_stoch.py
@@ -46,7 +46,7 @@ def generate_stoch(
     srf2stoch_path: Annotated[Path, typer.Option(exists=True)] = Path(
         "/EMOD3D/tools/srf2stoch"
     ),
-):
+) -> None:
     """Generate a stoch file from an SRF file.
 
     This function uses the `srf2stoch` binary to generate a stoch file from the provided SRF file.
diff --git a/workflow/scripts/generate_velocity_model_parameters.py b/workflow/scripts/generate_velocity_model_parameters.py
index 3eda0ddf..3ffed444 100644
--- a/workflow/scripts/generate_velocity_model_parameters.py
+++ b/workflow/scripts/generate_velocity_model_parameters.py
@@ -405,7 +405,7 @@ def pgv_target(
 @log_utils.log_call()
 def generate_velocity_model_parameters(
     realisation_ffp: Annotated[Path, typer.Argument()],
-):
+) -> None:
     """Generate velocity model parameters for a given realisation file.
 
     This function reads the source and rupture propagation information and computes:
diff --git a/workflow/scripts/hf_sim.py b/workflow/scripts/hf_sim.py
index c438e264..0ded2fd9 100644
--- a/workflow/scripts/hf_sim.py
+++ b/workflow/scripts/hf_sim.py
@@ -193,7 +193,7 @@ def run_hf(
         Path,
         typer.Option(exists=True, writable=True, file_okay=False),
     ] = Path("/out"),
-):
+) -> None:
     """Run the HF (High-Frequency) simulation and generate the HF output file.
 
     This function performs the following steps:
diff --git a/workflow/scripts/nshm2022_to_realisation.py b/workflow/scripts/nshm2022_to_realisation.py
index 23fd970d..06e1288e 100755
--- a/workflow/scripts/nshm2022_to_realisation.py
+++ b/workflow/scripts/nshm2022_to_realisation.py
@@ -158,7 +158,7 @@ def generate_realisation(
             max=1,
         ),
     ] = None,
-):
+) -> None:
     """Generate realisation stub files from ruptures in the NSHM 2022 database.
 
     This function initializes a connection to the NSHM database, retrieves
diff --git a/workflow/scripts/plan_workflow.py b/workflow/scripts/plan_workflow.py
index 93ae3d0d..e13bc09f 100644
--- a/workflow/scripts/plan_workflow.py
+++ b/workflow/scripts/plan_workflow.py
@@ -708,7 +708,7 @@ def plan_workflow(
     ] = None,
     container: Annotated[Optional[Path], typer.Option()] = None,
     emod3d_path: Annotated[Optional[Path], typer.Option()] = None,
-):
+) -> None:
     """Plan and generate a Cylc workflow file for a number of realisations.
 
     Parameters
diff --git a/workflow/scripts/realisation_to_srf.py b/workflow/scripts/realisation_to_srf.py
index 0cd3af52..a470074c 100644
--- a/workflow/scripts/realisation_to_srf.py
+++ b/workflow/scripts/realisation_to_srf.py
@@ -130,7 +130,7 @@ def generate_fault_srf(
     srf_config: SRFConfig,
     seeds: Seeds,
     genslip_path: Path,
-):
+) -> None:
     """Generate an SRF file for a given fault.
 
     Parameters
@@ -450,7 +450,7 @@ def generate_fault_srfs_parallel(
     seeds: Seeds,
     velocity_model_1d: VelocityModel1D,
     genslip_path: Path,
-):
+) -> None:
     """Generate fault SRF files in parallel.
 
     Parameters
@@ -524,7 +524,7 @@ def generate_srf(
     genslip_path: Annotated[Path, typer.Option(readable=True, dir_okay=False)] = Path(
         "/EMOD3D/tools/genslip_v5.4.2"
     ),
-):
+) -> None:
     """Generate an SRF file from a given realisation specification.
 
     This function reads the realisation metadata and configurations from the specified YAML file. It then generates