diff --git a/.github/build-ci/manifests/access_esm3/intel.spack.yaml.j2 b/.github/build-ci/manifests/access_esm3/intel.spack.yaml.j2
new file mode 100644
index 00000000..6ca5eef5
--- /dev/null
+++ b/.github/build-ci/manifests/access_esm3/intel.spack.yaml.j2
@@ -0,0 +1,29 @@
+spack:
+  specs:
+  # package is defined in the workflows inputs.spack-manifest-data-pairs
+  # intel_compiler_ver is defined in the standard_definitions.json data file
+  - '{{ package }}'
+  packages:
+    access3:
+      require:
+      - 'configurations=MOM6-CICE6-UM13,MOM6-UM13'
+    um:
+      require:
+      - '@13.0'
+      - casim_ref=um13.0 jules_ref=JULES_vn7.0 shumlib_ref=um13.0 socrates_ref=um13.0 ukca_ref=b42593d0c8fe744f9cc1d1556a664fec792f4766 um_ref=vn13.0_nuopc_esmf_flags
+    access-cice:
+      require:
+      - '@git.3286c36f9b9125ffddbc4d3aa9f98ff87ae1aded=CICE6.6.3-0'
+    python:
+      require:
+        - '@3.11.14'
+    intel-oneapi-compilers-classic:
+      require:
+        - '{{ intel_compiler_ver }}'
+    all:
+      require:
+        - '%access_intel'
+        - 'target={{ target }}'
+  concretizer:
+    unify: false
+  view: false
diff --git a/spack_repo/access/nri/build_systems/um_base.py b/spack_repo/access/nri/build_systems/um_base.py
index cbd4376d..2f89a2db 100644
--- a/spack_repo/access/nri/build_systems/um_base.py
+++ b/spack_repo/access/nri/build_systems/um_base.py
@@ -158,7 +158,7 @@ class UmBasePackage(Package):
         when="+DR_HOOK")
     depends_on("eccodes +fortran +netcdf", type=("build", "link", "run"),
         when="+eccodes")
-    depends_on("netcdf-fortran@4.5.2", type=("build", "link", "run"),
+    depends_on("netcdf-fortran@4.5.2:", type=("build", "link", "run"),
         when="+netcdf")
 
     phases = ["build", "install"]
diff --git a/spack_repo/access/nri/packages/access3/package.py b/spack_repo/access/nri/packages/access3/package.py
index 6bad832f..90505f3c 100644
--- a/spack_repo/access/nri/packages/access3/package.py
+++ b/spack_repo/access/nri/packages/access3/package.py
@@ -14,6 +14,8 @@
     "MOM6-CICE6",
     "CICE6-WW3",
     "MOM6-CICE6-WW3",
+    "MOM6-UM13",
+    "MOM6-CICE6-UM13",
 )
 
 # tag,commit pairs for releases in access3-share git repository
@@ -78,6 +80,12 @@ class Access3(CMakePackage):
             depends_on("access-mom6@2025.02.000: +access3", when=f"configurations={conf}")
         if "WW3" in conf:
             depends_on("access-ww3@2025.03.0: +access3", when=f"configurations={conf}")
+        if "UM13" in conf:
+            conflicts('@:2026.03.001')
+            depends_on("um +access3+netcdf~eccodes~DR_HOOK", when=f"configurations={conf}")
+        if "CICE6" in conf and "UM13" in conf:
+            # Set the driver variant for the UM-CICE coupling code
+            depends_on("access-cice driver=access/cmeps", when=f"configurations={conf}")
 
     def cmake_args(self):
         # make configurations a cmake argument
diff --git a/spack_repo/access/nri/packages/access_esm3/package.py b/spack_repo/access/nri/packages/access_esm3/package.py
new file mode 100644
index 00000000..015e4b83
--- /dev/null
+++ b/spack_repo/access/nri/packages/access_esm3/package.py
@@ -0,0 +1,26 @@
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack_repo.builtin.build_systems.bundle import BundlePackage
+from spack.package import *
+
+
+class AccessEsm3(BundlePackage):
+    """
+    ACCESS-ESM3 bundle containing the ACCESS-EM3 Package.
+
+    This is used to version the entirety of a released deployment, including
+    the package, it's dependencies, and the version of
+    spack-packages/spack-config that it is bundled with
+    """
+
+    homepage = "https://www.access-nri.org.au"
+
+    git = "https://github.com/ACCESS-NRI/ACCESS-ESM3.git"
+
+    maintainers("anton-seaice")
+
+    version("latest")
+
+    depends_on("access3")
diff --git a/spack_repo/access/nri/packages/gcom/package.py b/spack_repo/access/nri/packages/gcom/package.py
index 12834c14..0004c7c8 100644
--- a/spack_repo/access/nri/packages/gcom/package.py
+++ b/spack_repo/access/nri/packages/gcom/package.py
@@ -5,6 +5,7 @@
 # Copyright 2024-2026 ACCESS-NRI
 
 from spack_repo.builtin.build_systems.generic import Package
+from spack.version.version_types import GitVersion, StandardVersion
 from spack.package import *
 
 
@@ -86,7 +87,46 @@ def install(self, spec, prefix):
         # Do the build with fcm
         fcm("make", "-f", "fcm-make/gcom.cfg")
 
+        self.__create_pkgconfig(spec, prefix)
+
         # Install the library
         mkdirp(prefix.lib)
         install("build/lib/libgcom.a", prefix.lib + "/libgcom.a")
+        install_tree("build/lib/pkgconfig", prefix.lib + "/pkgconfig")
         install_tree("build/include", prefix.include)
+
+    def __create_pkgconfig(self, spec, prefix):
+
+        # Workaround for https://github.com/spack/spack/issues/50118
+        Version = self.spec.version
+        if isinstance(Version, GitVersion):
+            version_str = Version.ref_version.string
+        elif isinstance(Version, StandardVersion):
+            version_str = Version.string
+        else:
+            version_str = "unknown"
+
+        # Location to install pkgconf file
+        pkgdir = "build/lib/pkgconfig"
+        mkdirp(pkgdir)
+
+        k = "gcom"
+        lib = f"lib{k}"
+        text = f"""\
+prefix={prefix}
+exec_prefix=${{prefix}}
+libdir=${{exec_prefix}}/lib
+includedir=${{prefix}}/include
+
+Name: {lib}
+Description: GCOM {version_str} {lib} Library for Fortran
+Version: {version_str}
+Libs: -L${{libdir}} -l{k}
+Cflags: -I${{includedir}}
+"""
+        pcpath = join_path(pkgdir, f"{lib}.pc")
+        with open(pcpath, "w", encoding="utf-8") as pc:
+            nchars_written = pc.write(text)
+
+        if nchars_written < len(text):
+            raise OSError
\ No newline at end of file
diff --git a/spack_repo/access/nri/packages/um/package.py b/spack_repo/access/nri/packages/um/package.py
index ab907e05..a1c34370 100644
--- a/spack_repo/access/nri/packages/um/package.py
+++ b/spack_repo/access/nri/packages/um/package.py
@@ -6,7 +6,9 @@
 # Based on https://github.com/nci/spack-repo/blob/main/packages/um/package.py
 
 from spack_repo.access.nri.build_systems.um_base import UmBasePackage
+from spack.version.version_types import StandardVersion
 from spack.package import *
+from os.path import exists
 
 class Um(UmBasePackage):
     """
@@ -41,24 +43,96 @@ class Um(UmBasePackage):
     variant("mpi", default=True, description="Build with MPI")
     depends_on("mpi", when="+mpi", type=("build", "link", "run"))
 
+    variant("access3", default=False,
+        description="Install UM as library for Access3 models")
+
+    with when("+access3"):
+        depends_on("esmf@8.7.0:")
+        conflicts("~netcdf")
+
+    phases = ["build", "create_pkgconfig", "install"]
+
+
     def setup_run_environment(self, env):
         """
         Set the built path into the environment.
         """
         # Add the built executables to the path
-        env.prepend_path("PATH", join_path(self.prefix, "build-atmos", "bin"))
+        if not self.spec.variants["access3"].value:
+            env.prepend_path("PATH", join_path(self.prefix, "build-atmos", "bin"))
         env.prepend_path("PATH", join_path(self.prefix, "build-recon", "bin"))
 
 
     def install(self, spec, prefix):
         """
-        Install executables and accompanying files into the prefix directory,
-        according to the directory structure of EXEC_DIR, as described in (e.g.)
-        https://code.metoffice.gov.uk/trac/roses-u/browser/b/y/3/9/5/trunk/meta/rose-meta.conf
+        Install executables and libraries into spack release folder (prefix)
+        When ~access3, this package installs um-atmos.exe
+        When +access3, the package installs libum-atmos.a
+        um-recon.exe is always installed.
         """
-        for um_exe in ["atmos", "recon"]:
-            bin_dir = join_path(f"build-{um_exe}", "bin")
+
+        # List of executables to install, always install recon
+        um_exe = ["recon"]
+
+        if self.spec.variants["access3"].value:
+            # Install library files from build-atmos directory straight into prefix path
+            # so it is in the expected CMAKE_PREFIX_PATH for dependents
+            for dir_name in ["lib", "include"]:
+                dir_path = join_path("build-atmos", dir_name)
+                build_dir = join_path(self.build_dir(), dir_path)
+                install_dir = join_path(prefix, dir_name)
+                mkdirp(install_dir)
+                install_tree(build_dir, install_dir)
+        else:
+            # Install atmos executable
+            um_exe.append("atmos")
+
+        # Install executables and accompanying files into the prefix directory,
+        # according to the directory structure of EXEC_DIR, as described in (e.g.)
+        # https://code.metoffice.gov.uk/trac/roses-u/browser/b/y/3/9/5/trunk/meta/rose-meta.conf
+        for exe in um_exe:
+            bin_dir = join_path(f"build-{exe}", "bin")
             build_bin_dir = join_path(self.build_dir(), bin_dir)
             install_bin_dir = join_path(prefix, bin_dir)
             mkdirp(install_bin_dir)
             install_tree(build_bin_dir, install_bin_dir)
+
+    def create_pkgconfig(self, spec, prefix):
+        """
+        If a um-atmos library has been created, make a pkgconfig file for it
+        """
+        k = "um-atmos"
+        libdir = f"{self.build_dir()}/build-atmos/lib"
+        lib = f"lib{k}"
+
+        if exists(f"{libdir}/{lib}.a"):
+
+            pkgdir = f"{libdir}/pkgconfig"
+            mkdirp(pkgdir)
+
+            # Workaround for https://github.com/spack/spack/issues/50118
+            Version = self.spec.version
+            if isinstance(Version, StandardVersion):
+                version_str = Version.string
+            else:
+                version_str = "unknown"
+
+            text = f"""\
+prefix={prefix}
+exec_prefix=${{prefix}}
+libdir=${{exec_prefix}}/lib
+includedir=${{prefix}}/include
+
+Name: {lib}
+Description: UM {version_str} {lib} Library for Fortran
+Version: {version_str}
+Requires: libgcom
+Libs: -L${{libdir}} -l{k}
+Cflags: -I${{includedir}}
+"""
+            pcpath = join_path(pkgdir, f"{lib}.pc")
+            with open(pcpath, "w", encoding="utf-8") as pc:
+                nchars_written = pc.write(text)
+
+            if nchars_written < len(text):
+                raise OSError
\ No newline at end of file