diff --git a/asaas/request.go b/asaas/request.go
index b2d151f..dcd928c 100644
--- a/asaas/request.go
+++ b/asaas/request.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
-	"fmt"
 	"github.com/GabrielHCataldo/go-asaas/internal/util"
 	"io"
 	"mime/multipart"
@@ -12,7 +11,6 @@ import (
 	"net/url"
 	"os"
 	"reflect"
-	"strconv"
 	"strings"
 )
 
@@ -94,12 +92,12 @@ func (r request[T]) createHttpRequest(ctx context.Context, method string, path s
 			for i := 0; i < rPayload.NumField(); i++ {
 				f := rPayload.Field(i)
 				ft := rtPayload.Field(i)
-				k := util.GetJsonFieldNameByReflect(ft)
-				v := util.GetValueByReflect(f)
+				k := util.GetJsonFieldNameByReflectField(ft)
+				v := util.GetValueByReflectField(f)
 				if util.IsBlank(&k) || v == nil {
 					continue
 				}
-				params.Add(k, fmt.Sprintf(`%s`, v))
+				params.Add(k, util.ConvertToString(v))
 			}
 			encode := params.Encode()
 			if util.IsNotBlank(&encode) {
@@ -193,26 +191,14 @@ func (r request[T]) prepareMultipartPayload(payload any) (map[string][]io.Reader
 	for i := 0; i < rPayload.NumField(); i++ {
 		fd := rPayload.Field(i)
 		ft := rtPayload.Field(i)
-		if fd.IsZero() || !fd.IsValid() {
+		k := util.GetJsonFieldNameByReflectField(ft)
+		vf := util.GetValueByReflectField(fd)
+		if vf == nil {
 			continue
 		}
-		k := util.GetJsonFieldNameByReflect(ft)
-		vf := util.GetValueByReflect(fd)
-		var b bool
-		var s string
-		var in int
-		var f *os.File
-		var fs []*os.File
-		var ok bool
-		if b, ok = vf.(bool); ok {
-			multipartPayload[k] = []io.Reader{strings.NewReader(strconv.FormatBool(b))}
-		} else if s, ok = vf.(string); ok {
-			multipartPayload[k] = []io.Reader{strings.NewReader(s)}
-		} else if in, ok = vf.(int); ok {
-			multipartPayload[k] = []io.Reader{strings.NewReader(strconv.Itoa(in))}
-		} else if f, ok = vf.(*os.File); ok && f != nil {
+		if f, fOk := vf.(*os.File); fOk && f != nil {
 			multipartPayload[k] = []io.Reader{f}
-		} else if fs, ok = vf.([]*os.File); ok && fs != nil {
+		} else if fs, fsOk := vf.([]*os.File); fsOk && fs != nil {
 			var files []io.Reader
 			for _, file := range fs {
 				if file != nil {
@@ -220,8 +206,8 @@ func (r request[T]) prepareMultipartPayload(payload any) (map[string][]io.Reader
 				}
 			}
 			multipartPayload[k] = files
-		} else if vf != nil {
-			multipartPayload[k] = []io.Reader{strings.NewReader(fmt.Sprintf(`%s`, vf))}
+		} else {
+			multipartPayload[k] = []io.Reader{strings.NewReader(util.ConvertToString(vf))}
 		}
 	}
 	return multipartPayload, nil
diff --git a/asaas/test 1814882393.txt b/asaas/test 1814882393.txt
new file mode 100644
index 0000000..7cd8f77
--- /dev/null
+++ b/asaas/test 1814882393.txt	
@@ -0,0 +1 @@
+unit test golang
\ No newline at end of file
diff --git a/asaas/test 1919830447.txt b/asaas/test 1919830447.txt
new file mode 100644
index 0000000..7cd8f77
--- /dev/null
+++ b/asaas/test 1919830447.txt	
@@ -0,0 +1 @@
+unit test golang
\ No newline at end of file
diff --git a/internal/util/util.go b/internal/util/util.go
index d79afc5..e8cb354 100644
--- a/internal/util/util.go
+++ b/internal/util/util.go
@@ -2,6 +2,7 @@ package util
 
 import (
 	"encoding/json"
+	"fmt"
 	"os"
 	"path"
 	"reflect"
@@ -41,20 +42,29 @@ func GetSystemInfo(skipCaller int) (fileName string, line string, funcName strin
 	return fileBase, strconv.Itoa(lineInt), nameFunc
 }
 
-func GetValueByReflect(f reflect.Value) any {
+func GetValueByReflectField(f reflect.Value) any {
 	if f.IsZero() || !f.IsValid() {
 		return nil
 	}
-	v := f.Interface()
-	if x, ok := v.(*os.File); ok {
-		v = x
+	k := f.Kind()
+	if x, ok := f.Interface().(*os.File); ok {
+		return x
 	} else if f.Kind() == reflect.Pointer {
-		v = f.Elem().Interface()
+		f = f.Elem()
+		k = f.Kind()
 	}
-	return v
+	switch k {
+	case reflect.String:
+		return f.String()
+	case reflect.Int:
+		return f.Int()
+	case reflect.Bool:
+		return f.Bool()
+	}
+	return f.Interface()
 }
 
-func GetJsonFieldNameByReflect(f reflect.StructField) string {
+func GetJsonFieldNameByReflectField(f reflect.StructField) string {
 	sk := strings.Split(f.Tag.Get("json"), ",")
 	return sk[0]
 }
@@ -76,3 +86,18 @@ func IsJson(v []byte) bool {
 	}
 	return false
 }
+
+func ConvertToString(v any) string {
+	if v == nil {
+		return ""
+	} else if i, iOk := v.(int); iOk {
+		return strconv.Itoa(i)
+	} else if b, bOk := v.(bool); bOk {
+		return strconv.FormatBool(b)
+	} else if f64, f64Ok := v.(float64); f64Ok {
+		return strconv.FormatFloat(f64, 'f', -1, 64)
+	} else if s, sOk := v.(string); sOk {
+		return s
+	}
+	return fmt.Sprintf(`"%s"`, v)
+}