diff --git a/engine/suretax_test.go b/engine/suretax_test.go
index 572df5515..fdf06758b 100644
--- a/engine/suretax_test.go
+++ b/engine/suretax_test.go
@@ -84,3 +84,143 @@ func TestNewSureTaxRequest(t *testing.T) {
 		t.Errorf("Expecting:\n%s\nReceived:\n%s", string(eSureTaxRequest.Request), string(stReq.Request))
 	}
 }
+
+func TestSuretaxNewSureTaxRequestNilCfg(t *testing.T) {
+	CGRID := utils.Sha1("testOriginID", time.Date(2021, 1, 1, 8, 42, 20, 0, time.UTC).String())
+	cdr := &CDR{CGRID: CGRID,
+		OrderID:     123,
+		ToR:         utils.MetaVoice,
+		OriginID:    "testOriginID",
+		OriginHost:  "192.168.1.1",
+		Source:      utils.UnitTest,
+		RequestType: utils.MetaRated,
+		Tenant:      "cgrates.org",
+		Category:    "call",
+		Account:     "1001",
+		Subject:     "1001",
+		Destination: "1002",
+		SetupTime:   time.Date(2021, 1, 1, 8, 42, 20, 0, time.UTC),
+		AnswerTime:  time.Date(2021, 1, 1, 8, 42, 26, 0, time.UTC),
+		RunID:       utils.MetaDefault,
+		Usage:       12 * time.Second,
+		ExtraFields: map[string]string{"field_extr1": "val_extr1", "fieldextr2": "valextr2"},
+		Cost:        1.01, PreRated: true,
+	}
+	var stCfg *config.SureTaxCfg
+
+	experr := "invalid SureTax config"
+	stReq, err := NewSureTaxRequest(cdr, stCfg)
+
+	if err == nil || err.Error() != experr {
+		t.Fatalf("\nExpected: %q, \nReceived: %q", experr, err)
+	}
+
+	if stReq != nil {
+		t.Errorf("\nExpected: <%+v>, \nReceived: <%+v>",
+			nil, stReq)
+	}
+}
+
+func TestSuretaxNewSureTaxRequestInvalidUnits(t *testing.T) {
+	CGRID := utils.Sha1("testOriginID", time.Date(2021, 1, 1, 8, 42, 20, 0, time.UTC).String())
+	cdr := &CDR{CGRID: CGRID, OrderID: 123, ToR: utils.MetaVoice,
+		OriginID: "testOriginID", OriginHost: "192.168.1.1",
+		Source: utils.UnitTest, RequestType: utils.MetaRated,
+		Tenant: "cgrates.org", Category: "call", Account: "1001",
+		Subject: "1001", Destination: "1002",
+		SetupTime:   time.Date(2021, 1, 1, 8, 42, 20, 0, time.UTC),
+		AnswerTime:  time.Date(2021, 1, 1, 8, 42, 26, 0, time.UTC),
+		RunID:       utils.MetaDefault,
+		Usage:       12 * time.Second,
+		ExtraFields: map[string]string{"field_extr1": "val_extr1", "fieldextr2": "valextr2"},
+		Cost:        1.01, PreRated: true,
+	}
+	cfg := config.NewDefaultCGRConfig()
+	stCfg := cfg.SureTaxCfg()
+	stCfg.Units = nil
+	stCfg.ClientNumber = "000000000"
+	stCfg.ValidationKey = "19491161-F004-4F44-BDB3-E976D6739A64"
+	stCfg.Timezone = time.UTC
+	experr := "strconv.ParseInt: parsing \"\": invalid syntax"
+	stReq, err := NewSureTaxRequest(cdr, stCfg)
+
+	if err == nil || err.Error() != experr {
+		t.Fatalf("\nExpected: %q, \nReceived: %q", experr, err)
+	}
+
+	if stReq != nil {
+		t.Errorf("\nExpected: <%+v>, \nReceived: <%+v>",
+			nil, stReq)
+	}
+}
+
+// func TestSuretaxNewSureTaxRequest3(t *testing.T) {
+// 	CGRID := utils.Sha1("testOriginID", time.Date(2013, 11, 7, 8, 42, 20, 0, time.UTC).String())
+// 	cdr := &CDR{
+// 		CGRID:       CGRID,
+// 		OrderID:     123,
+// 		ToR:         utils.MetaVoice,
+// 		OriginID:    "testOriginID",
+// 		OriginHost:  "192.168.1.1",
+// 		Source:      utils.UnitTest,
+// 		RequestType: utils.MetaRated,
+// 		Tenant:      "cgrates.org",
+// 		Category:    "call",
+// 		Account:     "1001",
+// 		Subject:     "1001",
+// 		Destination: "1002",
+// 		SetupTime:   time.Date(2013, 11, 7, 8, 42, 20, 0, time.UTC),
+// 		AnswerTime:  time.Date(2013, 11, 7, 8, 42, 26, 0, time.UTC),
+// 		RunID:       utils.MetaDefault,
+// 		Usage:       12 * time.Second,
+// 		ExtraFields: map[string]string{"field_extr1": "val_extr1", "fieldextr2": "valextr2"},
+// 		Cost:        1.01, PreRated: true,
+// 	}
+// 	cfg := config.NewDefaultCGRConfig()
+// 	stCfg := cfg.SureTaxCfg()
+// 	stCfg.ClientNumber = "000000000"
+// 	stCfg.ValidationKey = "19491161-F004-4F44-BDB3-E976D6739A64"
+// 	stCfg.Timezone = time.UTC
+
+// 	experr := ""
+// 	stReq, err := NewSureTaxRequest(cdr, stCfg)
+
+// 	if err == nil || err.Error() != experr {
+// 		t.Fatalf("\nExpected: %q, \nReceived: %q", experr, err)
+// 	}
+
+// 	if stReq != nil {
+// 		t.Errorf("\nExpected: <%+v>, \nReceived: <%+v>", nil, stReq)
+// 	}
+// }
+
+func TestSuretaxSureTaxProcessCdrPostFail(t *testing.T) {
+	CGRID := utils.Sha1("testOriginID", time.Date(2021, 1, 1, 8, 42, 20, 0, time.UTC).String())
+	cdr := &CDR{
+		CGRID:       CGRID,
+		OrderID:     123,
+		ToR:         utils.MetaVoice,
+		OriginID:    "testOriginID",
+		OriginHost:  "192.168.1.1",
+		Source:      utils.UnitTest,
+		RequestType: utils.MetaRated,
+		Tenant:      "cgrates.org",
+		Category:    "call",
+		Account:     "1001",
+		Subject:     "1001",
+		Destination: "1002",
+		SetupTime:   time.Date(2021, 1, 1, 8, 42, 20, 0, time.UTC),
+		AnswerTime:  time.Date(2021, 1, 1, 8, 42, 26, 0, time.UTC),
+		RunID:       utils.MetaDefault,
+		Usage:       12 * time.Second,
+		ExtraFields: map[string]string{"field_extr1": "val_extr1", "fieldextr2": "valextr2"},
+		Cost:        1.01, PreRated: true,
+	}
+
+	experr := `Post "": unsupported protocol scheme ""`
+	err := SureTaxProcessCdr(cdr)
+
+	if err == nil || err.Error() != experr {
+		t.Errorf("\nExpected: %q, \nReceived: %q", experr, err)
+	}
+}