diff --git a/.gitignore b/.gitignore
index 8af6ec7..5007c32 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,4 +15,4 @@
 # Dependency directories (remove the comment below to include it)
 # vendor/
 
-test/.~lock*
+*.~lock*
diff --git a/go.mod b/go.mod
index d45e953..359a147 100644
--- a/go.mod
+++ b/go.mod
@@ -5,4 +5,5 @@ go 1.16
 require (
 	github.com/360EntSecGroup-Skylar/excelize/v2 v2.3.2
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/matryer/is v1.4.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 16ce853..d8e12a7 100644
--- a/go.sum
+++ b/go.sum
@@ -3,6 +3,8 @@ github.com/360EntSecGroup-Skylar/excelize/v2 v2.3.2/go.mod h1:xc0ybJZXcn084ZaIvQ
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/matryer/is v1.4.0 h1:sosSmIWwkYITGrxZ25ULNDeKiMNzFSr4V/eqBQP0PeE=
+github.com/matryer/is v1.4.0/go.mod h1:8I/i5uYgLzgsgEloJE1U6xx5HkBQpAZvepWuujKwMRU=
 github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 h1:RWengNIwukTxcDr9M+97sNutRR1RKhG96O6jWumTTnw=
 github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826/go.mod h1:TaXosZuwdSHYgviHp1DAtfrULt5eUgsSMsZf+YrPgl8=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
diff --git a/pkg/loader/conf/default.json b/pkg/loader/conf/default.json
index 79fb080..c824ae0 100644
--- a/pkg/loader/conf/default.json
+++ b/pkg/loader/conf/default.json
@@ -128,7 +128,7 @@
             "default": "Please choose"
           },
           {
-            "col": "E",
+            "col": "F",
             "field": "Costs",
             "type": "string",
             "default": "0"
diff --git a/pkg/loader/loader.go b/pkg/loader/loader.go
index ff9dc6d..3ec198b 100644
--- a/pkg/loader/loader.go
+++ b/pkg/loader/loader.go
@@ -43,14 +43,20 @@ func XLSX(r io.Reader, conf *Conf) (*ecalc.Ecalc, error) {
 			for r := a.StartRow; r <= a.EndRow; r++ {
 				sf := ecalc.SupplyFraction{}
 				for _, c := range a.Cols {
+					axis := fmt.Sprintf("%s%d", c.Col, r)
 					cellValue, err := xFile.GetCellValue(
 						xFile.GetSheetName(a.Sheet),
-						fmt.Sprintf("%s%d", c.Col, r),
+						axis,
 					)
 					if err != nil {
 						errs = append(errs, err)
 					}
-					set.Field(&sf, c.Field, cellValue)
+					err = set.Field(&sf, c.Field, cellValue)
+					if err != nil {
+						errs = append(errs,
+							fmt.Errorf("XLSXL.SupplyFraction: Sheet %d, Cell %s: %w",
+								a.Sheet, axis, err))
+					}
 				}
 				eBalance.CompanyFacts.SupplyFractions =
 					append(
diff --git a/pkg/loader/loader_test.go b/pkg/loader/loader_test.go
new file mode 100644
index 0000000..3f1460f
--- /dev/null
+++ b/pkg/loader/loader_test.go
@@ -0,0 +1,23 @@
+package loader
+
+import (
+	"bytes"
+	_ "embed"
+	"testing"
+
+	"github.com/matryer/is"
+)
+
+//go:embed test/testfile.xlsx
+var tb []byte
+
+func TestXLSX(t *testing.T) {
+	is := is.New(t)
+	buf := bytes.NewBuffer(tb)
+	got, err := XLSX(buf, nil)
+	is.NoErr(err)                 // no error for testfile
+	is.Equal(got.Version, "5.04") // version 5.04
+	is.Equal(got.CompanyFacts.TotalPurchaseFromSuppliers, 10000)
+	is.Equal(got.CompanyFacts.SupplyFractions[0].Costs, 500)
+	is.Equal(got.CompanyFacts.SupplyFractions[0].CountryCode, "ALB")
+}
diff --git a/pkg/loader/test/testfile.xlsx b/pkg/loader/test/testfile.xlsx
new file mode 100644
index 0000000..2aca32c
Binary files /dev/null and b/pkg/loader/test/testfile.xlsx differ