diff --git a/disperser/apiserver/disperse_blob_v2.go b/disperser/apiserver/disperse_blob_v2.go
index af227f05e..2da6a4a24 100644
--- a/disperser/apiserver/disperse_blob_v2.go
+++ b/disperser/apiserver/disperse_blob_v2.go
@@ -117,9 +117,6 @@ func (s *DispersalServerV2) validateDispersalRequest(ctx context.Context, req *p
 	if blobHeader.PaymentMetadata == (core.PaymentMetadata{}) {
 		return api.NewErrorInvalidArg("payment metadata is required")
 	}
-	if err = s.authenticator.AuthenticateBlobRequest(blobHeader); err != nil {
-		return api.NewErrorInvalidArg(fmt.Sprintf("authentication failed: %s", err.Error()))
-	}
 
 	if len(blobHeader.PaymentMetadata.AccountID) == 0 || blobHeader.PaymentMetadata.ReservationPeriod == 0 || blobHeader.PaymentMetadata.CumulativePayment == nil {
 		return api.NewErrorInvalidArg("invalid payment metadata")
@@ -139,6 +136,10 @@ func (s *DispersalServerV2) validateDispersalRequest(ctx context.Context, req *p
 		}
 	}
 
+	if err = s.authenticator.AuthenticateBlobRequest(blobHeader); err != nil {
+		return api.NewErrorInvalidArg(fmt.Sprintf("authentication failed: %s", err.Error()))
+	}
+
 	// validate every 32 bytes is a valid field element
 	_, err = rs.ToFrArray(data)
 	if err != nil {