diff --git a/pkg/common/engine.go b/pkg/common/engine.go
index cacea43f..cf3ee7a6 100644
--- a/pkg/common/engine.go
+++ b/pkg/common/engine.go
@@ -84,6 +84,44 @@ func NormalizePlatformName(platform string) string {
 	return p
 }
 
+// Canonical tokens returned by NormalizeScopeName.
+const (
+	ScopeRegional = "regional"
+	ScopeZonal    = "zonal"
+)
+
+// NormalizeTenancyName normalizes an EC2 tenancy for comparison. "shared" is
+// the operator spelling of the API value "default"; "dedicated" and "host" stay
+// distinct. Unrecognized input returns "" (unknown, a wildcard). Mirrors the
+// accepted inputs of parseEC2Tenancy in providers/aws/services/ec2/client.go,
+// which pkg cannot import.
+func NormalizeTenancyName(tenancy string) string {
+	switch t := strings.ToLower(strings.TrimSpace(tenancy)); t {
+	case "default", "shared":
+		return "default"
+	case "dedicated", "host":
+		return t
+	default:
+		return ""
+	}
+}
+
+// NormalizeScopeName normalizes an EC2 reservation scope to ScopeRegional or
+// ScopeZonal. Unrecognized input returns "" (unknown, a wildcard). Mirrors
+// parseEC2Scope in providers/aws/services/ec2/client.go ("Region",
+// "Availability Zone", and the hyphenated legacy spelling), which pkg cannot
+// import.
+func NormalizeScopeName(scope string) string {
+	switch strings.ToLower(strings.TrimSpace(scope)) {
+	case "region", "regional":
+		return ScopeRegional
+	case "availability zone", "availability-zone", "zonal":
+		return ScopeZonal
+	default:
+		return ""
+	}
+}
+
 // EngineFilterKey returns the value the --include-engines/--exclude-engines
 // filters compare against, and the normalizer to apply to each filter entry.
 // Databases and caches use their engine; compute (EC2) uses its platform,
diff --git a/pkg/common/engine_test.go b/pkg/common/engine_test.go
index 54e07be0..357fa353 100644
--- a/pkg/common/engine_test.go
+++ b/pkg/common/engine_test.go
@@ -69,3 +69,38 @@ func TestEngineFromDetails(t *testing.T) {
 		})
 	}
 }
+
+func TestNormalizeTenancyName(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct{ in, want string }{
+		{"default", "default"},
+		{"Shared", "default"},
+		{"  SHARED ", "default"},
+		{"Dedicated", "dedicated"},
+		{"host", "host"},
+		{"Bogus", ""},
+		{"", ""},
+	}
+	for _, tt := range tests {
+		assert.Equal(t, tt.want, NormalizeTenancyName(tt.in), "input %q", tt.in)
+	}
+}
+
+func TestNormalizeScopeName(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct{ in, want string }{
+		{"Region", ScopeRegional},
+		{"regional", ScopeRegional},
+		{" REGIONAL ", ScopeRegional},
+		{"Availability Zone", ScopeZonal},
+		{"availability-zone", ScopeZonal},
+		{"Zonal", ScopeZonal},
+		{"", ""},
+		{"Bogus", ""},
+	}
+	for _, tt := range tests {
+		assert.Equal(t, tt.want, NormalizeScopeName(tt.in), "input %q", tt.in)
+	}
+}
diff --git a/pkg/common/types.go b/pkg/common/types.go
index d36c5e2a..120f2811 100644
--- a/pkg/common/types.go
+++ b/pkg/common/types.go
@@ -497,6 +497,14 @@ type Commitment struct {
 	// means StartDate is a precise timestamp; true means the real instant
 	// lies in [StartDate, StartDate+24h).
 	StartDateIsDay bool `json:"start_date_is_day,omitempty"`
+
+	// EC2 reserved-instance dimensions. Empty means unknown or a wildcard.
+	// Filled by the EC2 commitment listing from the reserved instance's
+	// product description, tenancy, scope and availability zone.
+	Platform         string `json:"platform,omitempty"`
+	Tenancy          string `json:"tenancy,omitempty"`
+	Scope            string `json:"scope,omitempty"`
+	AvailabilityZone string `json:"availability_zone,omitempty"`
 }
 
 // OfferingDetails represents cloud provider offering details.
diff --git a/pkg/common/types_test.go b/pkg/common/types_test.go
index d62698ab..6e2020ce 100644
--- a/pkg/common/types_test.go
+++ b/pkg/common/types_test.go
@@ -598,3 +598,25 @@ func TestCommitment_StartDateIsDayJSON(t *testing.T) {
 	require.NoError(t, err)
 	assert.Contains(t, string(b), `"start_date_is_day":true`)
 }
+
+func TestCommitment_EC2DimensionsJSON(t *testing.T) {
+	empty, err := json.Marshal(Commitment{})
+	require.NoError(t, err)
+	for _, key := range []string{`"platform"`, `"tenancy"`, `"scope"`, `"availability_zone"`} {
+		assert.NotContains(t, string(empty), key)
+	}
+
+	in := Commitment{Platform: "Linux/UNIX", Tenancy: "default", Scope: "Availability Zone", AvailabilityZone: "us-east-1a"}
+	raw, err := json.Marshal(in)
+	require.NoError(t, err)
+	assert.Contains(t, string(raw), `"availability_zone":"us-east-1a"`)
+	var out Commitment
+	require.NoError(t, json.Unmarshal(raw, &out))
+	assert.Equal(t, in, out)
+
+	var old Commitment
+	require.NoError(t, json.Unmarshal([]byte(`{"provider":"aws","commitment_id":"ri-1","count":2}`), &old))
+	assert.Equal(t, "ri-1", old.CommitmentID)
+	assert.Empty(t, old.Platform)
+	assert.Empty(t, old.AvailabilityZone)
+}