diff --git a/src/cmd/services/m3coordinator/ingest/write.go b/src/cmd/services/m3coordinator/ingest/write.go
index 12ff0476a8..9889c23d89 100644
--- a/src/cmd/services/m3coordinator/ingest/write.go
+++ b/src/cmd/services/m3coordinator/ingest/write.go
@@ -229,6 +229,10 @@ func (d *downsamplerAndWriter) writeToDownsampler(
 	unit xtime.Unit,
 	overrides WriteOptions,
 ) (bool, error) {
+	if err := tags.Validate(); err != nil {
+		return false, err
+	}
+
 	appender, err := d.downsampler.NewMetricsAppender()
 	if err != nil {
 		return false, err
@@ -433,6 +437,11 @@ func (d *downsamplerAndWriter) writeAggregatedBatch(
 		appender.NextMetric()
 
 		value := iter.Current()
+		if err := value.Tags.Validate(); err != nil {
+			multiErr = multiErr.Add(err)
+			continue
+		}
+
 		for _, tag := range value.Tags.Tags {
 			appender.AddTag(tag.Name, tag.Value)
 		}
diff --git a/src/cmd/services/m3coordinator/ingest/write_test.go b/src/cmd/services/m3coordinator/ingest/write_test.go
index 0af2afe6ac..43281876c1 100644
--- a/src/cmd/services/m3coordinator/ingest/write_test.go
+++ b/src/cmd/services/m3coordinator/ingest/write_test.go
@@ -35,6 +35,7 @@ import (
 	"github.com/m3db/m3/src/query/storage/m3"
 	testm3 "github.com/m3db/m3/src/query/test/m3"
 	"github.com/m3db/m3/src/query/ts"
+	xerrors "github.com/m3db/m3/src/x/errors"
 	"github.com/m3db/m3/src/x/ident"
 	"github.com/m3db/m3/src/x/instrument"
 	xsync "github.com/m3db/m3/src/x/sync"
@@ -80,6 +81,20 @@ var (
 			},
 		},
 	)
+	testBadTags = models.NewTags(3, nil).AddTags([]models.Tag{
+		{
+			Name:  []byte("standard_tag"),
+			Value: []byte("standard_tag_value"),
+		},
+		{
+			Name:  []byte("duplicate_tag"),
+			Value: []byte("duplicate_tag_value0"),
+		},
+		{
+			Name:  []byte("duplicate_tag"),
+			Value: []byte("duplicate_tag_value1"),
+		},
+	})
 
 	testDatapoints1 = []ts.Datapoint{
 		{
@@ -214,6 +229,28 @@ func TestDownsampleAndWrite(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestDownsampleAndWriteWithBadTags(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	downAndWrite, _, _ := newTestDownsamplerAndWriter(t, ctrl,
+		testDownsamplerAndWriterOptions{})
+
+	err := downAndWrite.Write(
+		context.Background(), testBadTags, testDatapoints1, xtime.Second, testAnnotation1, defaultOverride)
+	require.Error(t, err)
+
+	// Make sure we get a validation error for downsample code path
+	// and for the raw unaggregate write code path.
+	multiErr, ok := err.(xerrors.MultiError)
+	require.True(t, ok)
+	require.Equal(t, 2, multiErr.NumErrors())
+	// Make sure all are invalid params errors.
+	for _, err := range multiErr.Errors() {
+		require.True(t, xerrors.IsInvalidParams(err))
+	}
+}
+
 func TestDownsampleAndWriteWithDownsampleOverridesAndNoMappingRules(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
@@ -457,6 +494,63 @@ func TestDownsampleAndWriteBatch(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestDownsampleAndWriteBatchBadTags(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	downAndWrite, downsampler, session := newTestDownsamplerAndWriter(t, ctrl,
+		testDownsamplerAndWriterOptions{})
+
+	var (
+		mockSamplesAppender = downsample.NewMockSamplesAppender(ctrl)
+		mockMetricsAppender = downsample.NewMockMetricsAppender(ctrl)
+	)
+
+	entries := []testIterEntry{
+		{tags: testBadTags, datapoints: testDatapoints1, attributes: testAttributesGauge, annotation: testAnnotation1},
+		{tags: testTags2, datapoints: testDatapoints2, attributes: testAttributesGauge, annotation: testAnnotation2},
+	}
+
+	// Only expect to write non-bad tags.
+	mockMetricsAppender.
+		EXPECT().
+		SamplesAppender(zeroDownsamplerAppenderOpts).
+		Return(downsample.SamplesAppenderResult{SamplesAppender: mockSamplesAppender}, nil).Times(1)
+	for _, tag := range testTags2.Tags {
+		mockMetricsAppender.EXPECT().AddTag(tag.Name, tag.Value)
+	}
+	for _, dp := range testDatapoints2 {
+		mockSamplesAppender.EXPECT().AppendGaugeTimedSample(dp.Timestamp, dp.Value)
+	}
+	downsampler.EXPECT().NewMetricsAppender().Return(mockMetricsAppender, nil)
+
+	mockMetricsAppender.EXPECT().NextMetric().Times(2)
+	mockMetricsAppender.EXPECT().Finalize()
+
+	// Only expect to write non-bad tags.
+	for _, entry := range testEntries[1:] {
+		for _, dp := range entry.datapoints {
+			session.EXPECT().WriteTagged(
+				gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), dp.Value, gomock.Any(), entry.annotation,
+			)
+		}
+	}
+
+	iter := newTestIter(entries)
+	err := downAndWrite.WriteBatch(context.Background(), iter, WriteOptions{})
+	require.Error(t, err)
+
+	// Make sure we get a validation error for downsample code path
+	// and for the raw unaggregate write code path.
+	multiErr, ok := err.(xerrors.MultiError)
+	require.True(t, ok)
+	require.Equal(t, 2, multiErr.NumErrors())
+	// Make sure all are invalid params errors.
+	for _, err := range multiErr.Errors() {
+		require.True(t, xerrors.IsInvalidParams(err))
+	}
+}
+
 func TestDownsampleAndWriteBatchDifferentTypes(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
diff --git a/src/query/models/tags.go b/src/query/models/tags.go
index 17595e9396..08abde0087 100644
--- a/src/query/models/tags.go
+++ b/src/query/models/tags.go
@@ -28,6 +28,7 @@ import (
 	"strings"
 
 	"github.com/m3db/m3/src/metrics/generated/proto/metricpb"
+	xerrors "github.com/m3db/m3/src/x/errors"
 
 	"github.com/cespare/xxhash/v2"
 )
@@ -258,6 +259,16 @@ func (t Tags) Normalize() Tags {
 // Validate will validate there are tag values, and the
 // tags are ordered and there are no duplicates.
 func (t Tags) Validate() error {
+	// Wrap call to validate to make sure a validation error
+	// is always an invalid parameters error so we return bad request
+	// instead of internal server error at higher in the stack.
+	if err := t.validate(); err != nil {
+		return xerrors.NewInvalidParamsError(err)
+	}
+	return nil
+}
+
+func (t Tags) validate() error {
 	n := t.Len()
 	if n == 0 {
 		return errNoTags
diff --git a/src/query/models/tags_test.go b/src/query/models/tags_test.go
index 0669ae44fe..310eae7191 100644
--- a/src/query/models/tags_test.go
+++ b/src/query/models/tags_test.go
@@ -29,6 +29,7 @@ import (
 
 	"github.com/m3db/m3/src/query/graphite/graphite"
 	"github.com/m3db/m3/src/query/util/writer"
+	xerrors "github.com/m3db/m3/src/x/errors"
 	xtest "github.com/m3db/m3/src/x/test"
 
 	"github.com/cespare/xxhash/v2"
@@ -425,13 +426,17 @@ func TestWriteTagLengthMeta(t *testing.T) {
 func TestTagsValidateEmptyNameQuoted(t *testing.T) {
 	tags := NewTags(0, NewTagOptions().SetIDSchemeType(TypeQuoted))
 	tags = tags.AddTag(Tag{Name: []byte(""), Value: []byte("bar")})
-	require.Error(t, tags.Validate())
+	err := tags.Validate()
+	require.Error(t, err)
+	require.True(t, xerrors.IsInvalidParams(err))
 }
 
 func TestTagsValidateEmptyValueQuoted(t *testing.T) {
 	tags := NewTags(0, NewTagOptions().SetIDSchemeType(TypeQuoted))
 	tags = tags.AddTag(Tag{Name: []byte("foo"), Value: []byte("")})
-	require.Error(t, tags.Validate())
+	err := tags.Validate()
+	require.Error(t, err)
+	require.True(t, xerrors.IsInvalidParams(err))
 }
 
 func TestTagsValidateOutOfOrderQuoted(t *testing.T) {
@@ -446,7 +451,9 @@ func TestTagsValidateOutOfOrderQuoted(t *testing.T) {
 			Value: []byte("baz"),
 		},
 	}
-	require.Error(t, tags.Validate())
+	err := tags.Validate()
+	require.Error(t, err)
+	require.True(t, xerrors.IsInvalidParams(err))
 
 	// Test fixes after normalize.
 	tags.Normalize()
@@ -467,13 +474,17 @@ func TestTagsValidateDuplicateQuoted(t *testing.T) {
 		Name:  []byte("foo"),
 		Value: []byte("qux"),
 	})
-	require.Error(t, tags.Validate())
+	err := tags.Validate()
+	require.Error(t, err)
+	require.True(t, xerrors.IsInvalidParams(err))
 }
 
 func TestTagsValidateEmptyNameGraphite(t *testing.T) {
 	tags := NewTags(0, NewTagOptions().SetIDSchemeType(TypeGraphite))
 	tags = tags.AddTag(Tag{Name: nil, Value: []byte("bar")})
-	require.Error(t, tags.Validate())
+	err := tags.Validate()
+	require.Error(t, err)
+	require.True(t, xerrors.IsInvalidParams(err))
 }
 
 func TestTagsValidateOutOfOrderGraphite(t *testing.T) {
@@ -488,7 +499,9 @@ func TestTagsValidateOutOfOrderGraphite(t *testing.T) {
 			Value: []byte("bar"),
 		},
 	}
-	require.Error(t, tags.Validate())
+	err := tags.Validate()
+	require.Error(t, err)
+	require.True(t, xerrors.IsInvalidParams(err))
 
 	// Test fixes after normalize.
 	tags.Normalize()
@@ -509,7 +522,9 @@ func TestTagsValidateDuplicateGraphite(t *testing.T) {
 		Name:  graphite.TagName(1),
 		Value: []byte("baz"),
 	})
-	require.Error(t, tags.Validate())
+	err := tags.Validate()
+	require.Error(t, err)
+	require.True(t, xerrors.IsInvalidParams(err))
 }
 
 func buildTags(b *testing.B, count, length int, opts TagOptions, escape bool) Tags {