diff --git a/app/vminsert/influx/request_handler.go b/app/vminsert/influx/request_handler.go
index d6ae61bec..b046f1b73 100644
--- a/app/vminsert/influx/request_handler.go
+++ b/app/vminsert/influx/request_handler.go
@@ -15,6 +15,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/tenantmetrics"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/writeconcurrencylimiter"
 	"github.com/VictoriaMetrics/metrics"
+	"github.com/valyala/fastjson/fastfloat"
 )
 
 var (
@@ -33,7 +34,7 @@ var (
 func InsertHandlerForReader(at *auth.Token, r io.Reader) error {
 	return writeconcurrencylimiter.Do(func() error {
 		return parser.ParseStream(r, false, "", "", func(db string, rows []parser.Row) error {
-			return insertRows(at, db, rows)
+			return insertRows(at, db, rows, true)
 		})
 	})
 }
@@ -49,24 +50,34 @@ func InsertHandlerForHTTP(at *auth.Token, req *http.Request) error {
 		// Read db tag from https://docs.influxdata.com/influxdb/v1.7/tools/api/#write-http-endpoint
 		db := q.Get("db")
 		return parser.ParseStream(req.Body, isGzipped, precision, db, func(db string, rows []parser.Row) error {
-			return insertRows(at, db, rows)
+			return insertRows(at, db, rows, false)
 		})
 	})
 }
 
-func insertRows(at *auth.Token, db string, rows []parser.Row) error {
+func insertRows(at *auth.Token, db string, rows []parser.Row, mayOverrideAccountProjectID bool) error {
 	ctx := getPushCtx()
 	defer putPushCtx(ctx)
 
 	ic := &ctx.Common
 	ic.Reset() // This line is required for initializing ic internals.
 	rowsTotal := 0
+	atCopy := *at
 	for i := range rows {
 		r := &rows[i]
 		ic.Labels = ic.Labels[:0]
 		hasDBLabel := false
 		for j := range r.Tags {
 			tag := &r.Tags[j]
+			if mayOverrideAccountProjectID {
+				// Multi-tenancy support via custom tags.
+				if tag.Key == "VictoriaMetrics_AccountID" {
+					atCopy.AccountID = uint32(fastfloat.ParseUint64BestEffort(tag.Value))
+				}
+				if tag.Key == "VictoriaMetrics_ProjectID" {
+					atCopy.ProjectID = uint32(fastfloat.ParseUint64BestEffort(tag.Value))
+				}
+			}
 			if tag.Key == "db" {
 				hasDBLabel = true
 			}
@@ -75,7 +86,7 @@ func insertRows(at *auth.Token, db string, rows []parser.Row) error {
 		if len(db) > 0 && !hasDBLabel {
 			ic.AddLabel("db", db)
 		}
-		ic.MetricNameBuf = storage.MarshalMetricNameRaw(ic.MetricNameBuf[:0], at.AccountID, at.ProjectID, ic.Labels)
+		ic.MetricNameBuf = storage.MarshalMetricNameRaw(ic.MetricNameBuf[:0], atCopy.AccountID, atCopy.ProjectID, ic.Labels)
 		metricNameBufLen := len(ic.MetricNameBuf)
 		ctx.metricGroupBuf = append(ctx.metricGroupBuf[:0], r.Measurement...)
 		skipFieldKey := len(r.Fields) == 1 && *skipSingleField
@@ -94,14 +105,14 @@ func insertRows(at *auth.Token, db string, rows []parser.Row) error {
 			ic.Labels = ic.Labels[:len(ic.Labels)-1]
 			ic.AddLabel("", metricGroup)
 			ic.MetricNameBuf = storage.MarshalMetricLabelRaw(ic.MetricNameBuf[:metricNameBufLen], placeholderLabel)
-			storageNodeIdx := ic.GetStorageNodeIdx(at, ic.Labels)
-			if err := ic.WriteDataPointExt(at, storageNodeIdx, ic.MetricNameBuf, r.Timestamp, f.Value); err != nil {
+			storageNodeIdx := ic.GetStorageNodeIdx(&atCopy, ic.Labels)
+			if err := ic.WriteDataPointExt(&atCopy, storageNodeIdx, ic.MetricNameBuf, r.Timestamp, f.Value); err != nil {
 				return err
 			}
 		}
 		rowsTotal += len(r.Fields)
 	}
-	rowsInserted.Get(at).Add(rowsTotal)
+	rowsInserted.Get(&atCopy).Add(rowsTotal)
 	rowsPerInsert.Update(float64(rowsTotal))
 	return ic.FlushBufs()
 }