diff --git a/cmd/jimmctl/cmd/relation_test.go b/cmd/jimmctl/cmd/relation_test.go
index 209316430..a1e4d32fb 100644
--- a/cmd/jimmctl/cmd/relation_test.go
+++ b/cmd/jimmctl/cmd/relation_test.go
@@ -360,11 +360,11 @@ func (s *relationSuite) TestListRelations(c *gc.C) {
 	}, {
 		Object:       "group-group-1#member",
 		Relation:     "administrator",
-		TargetObject: "model-" + env.controllers[0].Name + ":" + env.models[0].OwnerIdentityName + "/" + env.models[0].Name,
+		TargetObject: "model-" + env.models[0].OwnerIdentityName + "/" + env.models[0].Name,
 	}, {
 		Object:       "user-" + env.users[1].Name,
 		Relation:     "administrator",
-		TargetObject: "applicationoffer-" + env.controllers[0].Name + ":" + env.applicationOffers[0].Model.OwnerIdentityName + "/" + env.applicationOffers[0].Model.Name + "." + env.applicationOffers[0].Name,
+		TargetObject: "applicationoffer-" + env.applicationOffers[0].URL,
 	}, {
 		Object:       "user-" + env.users[0].Name,
 		Relation:     "administrator",
diff --git a/internal/errors/errors.go b/internal/errors/errors.go
index 08fbc7695..26f4d57bc 100644
--- a/internal/errors/errors.go
+++ b/internal/errors/errors.go
@@ -122,7 +122,7 @@ const (
 	CodeStillAlive                   Code = apiparams.CodeStillAlive
 	CodeUnauthorized                 Code = jujuparams.CodeUnauthorized
 	CodeUpgradeInProgress            Code = jujuparams.CodeUpgradeInProgress
-	CodeFailedToParseTupleKey        Code = "failed to parse tuple object key"
+	CodeFailedToParseTupleKey        Code = "failed to parse tuple"
 	CodeFailedToResolveTupleResource Code = "failed resolve resource"
 	CodeOpenFGARequestFailed         Code = "failed request to OpenFGA"
 	CodeJWKSRetrievalFailed          Code = "jwks retrieval failure"
diff --git a/internal/jimm/access_test.go b/internal/jimm/access_test.go
index eddfa3b89..58292071e 100644
--- a/internal/jimm/access_test.go
+++ b/internal/jimm/access_test.go
@@ -605,6 +605,10 @@ func TestResolveTupleObjectHandlesErrors(t *testing.T) {
 			input: "abc",
 			want:  "failed to setup tag resolver: tag is not properly formatted",
 		},
+		{
+			input: "model-test-unknowncontroller-1:alice@canonical.com/test-model-1",
+			want:  "model not found",
+		},
 	}
 	for i, tc := range tests {
 		t.Run(fmt.Sprintf("test %d", i), func(t *testing.T) {
diff --git a/internal/jujuapi/access_control.go b/internal/jujuapi/access_control.go
index 5f8faf2d0..403359cc4 100644
--- a/internal/jujuapi/access_control.go
+++ b/internal/jujuapi/access_control.go
@@ -4,6 +4,7 @@ package jujuapi
 
 import (
 	"context"
+	"fmt"
 	"strconv"
 	"time"
 
@@ -198,7 +199,7 @@ func (r *controllerRoot) parseTuple(ctx context.Context, tuple apiparams.Relatio
 	// to be specific to the erroneous offender.
 	parseTagError := func(msg string, key string, err error) error {
 		zapctx.Debug(ctx, msg, zap.String("key", key), zap.Error(err))
-		return errors.E(op, errors.CodeFailedToParseTupleKey, err, msg+" "+key)
+		return errors.E(op, errors.CodeFailedToParseTupleKey, fmt.Errorf("%s, key %s: %w", msg, key, err))
 	}
 
 	if tuple.TargetObject == "" {
@@ -207,14 +208,14 @@ func (r *controllerRoot) parseTuple(ctx context.Context, tuple apiparams.Relatio
 	if tuple.TargetObject != "" {
 		targetTag, err := r.jimm.ParseTag(ctx, tuple.TargetObject)
 		if err != nil {
-			return nil, parseTagError("failed to parse tuple target object key", tuple.TargetObject, err)
+			return nil, parseTagError("failed to parse tuple target", tuple.TargetObject, err)
 		}
 		t.Target = targetTag
 	}
 	if tuple.Object != "" {
 		objectTag, err := r.jimm.ParseTag(ctx, tuple.Object)
 		if err != nil {
-			return nil, parseTagError("failed to parse tuple object key", tuple.Object, err)
+			return nil, parseTagError("failed to parse tuple object", tuple.Object, err)
 		}
 		t.Object = objectTag
 	}
diff --git a/internal/jujuapi/access_control_test.go b/internal/jujuapi/access_control_test.go
index 22fff1934..533d89dcf 100644
--- a/internal/jujuapi/access_control_test.go
+++ b/internal/jujuapi/access_control_test.go
@@ -935,6 +935,15 @@ func (s *accessControlSuite) TestListRelationshipTuples(c *gc.C) {
 	c.Assert(err, jc.ErrorIsNil)
 	c.Assert(response.Tuples, jc.DeepEquals, []apiparams.RelationshipTuple{tuples[3]})
 	c.Assert(len(response.Errors), gc.Equals, 0)
+
+	// Test error message when a resource is not found
+	_, err = client.ListRelationshipTuples(&apiparams.ListRelationshipTuplesRequest{
+		Tuple: apiparams.RelationshipTuple{
+			TargetObject: "applicationoffer-" + "fake-offer",
+		},
+		ResolveUUIDs: true,
+	})
+	c.Assert(err, gc.ErrorMatches, "failed to parse tuple target, key applicationoffer-fake-offer: application offer not found.*")
 }
 
 func (s *accessControlSuite) TestListRelationshipTuplesNoUUIDResolution(c *gc.C) {