diff --git a/main.go b/main.go
index 92262e2..bf4fdbc 100644
--- a/main.go
+++ b/main.go
@@ -1,7 +1,10 @@
 package main
 
 import (
+	"bytes"
 	"embed"
+	"encoding/json"
+	"errors"
 	"fmt"
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
@@ -10,6 +13,7 @@ import (
 	"github.com/stripe/stripe-go/v72/checkout/session"
 	"github.com/stripe/stripe-go/v72/paymentintent"
 	"html/template"
+	"io"
 	"log"
 	"net/http"
 	"payment-poc/migration"
@@ -39,6 +43,7 @@ func init() {
 	godotenv.Load()
 
 	BackendUrl = envMustExist("BACKEND_URL")
+
 	WsPayShopId = envMustExist("WSPAY_SHOP_ID")
 	WsPayShopSecret = envMustExist("WSPAY_SHOP_SECRET")
 
@@ -493,6 +498,124 @@ func setupWsPayEndpoints(g *gin.RouterGroup, wspayService wspay.Service) {
 
 		c.HTML(200, "wspay.gohtml", gin.H{"Action": wspay.AuthorisationForm, "Form": form})
 	})
+	g.POST("complete/:id", func(c *gin.Context) {
+		id := uuid.MustParse(c.Param("id"))
+		amount, err := strconv.ParseFloat(c.PostForm("amount"), 64)
+		if err != nil {
+			c.AbortWithError(http.StatusBadRequest, err)
+			return
+		}
+		entry, err := wspayService.FetchById(id)
+		if err != nil {
+			c.AbortWithError(http.StatusNotFound, err)
+			return
+		}
+		if int64(amount*100) > entry.TotalAmount || int64(amount*100) < 1 {
+			c.AbortWithError(http.StatusBadRequest, err)
+			return
+		}
+		if entry.State == state.StateAccepted {
+			var request = wspay.WsPayCompletionRequest{
+				Version:      "2.0",
+				WsPayOrderId: entry.ShoppingCartID,
+				ShopId:       entry.ShopID,
+				ApprovalCode: entry.ApprovalCode,
+				STAN:         entry.STAN,
+				Amount:       int64(amount * 100),
+				Signature:    wspay.CalculateCompletionSignature(WsPayShopId, WsPayShopSecret, entry.ShoppingCartID, entry.STAN, entry.ApprovalCode, int64(amount*100)),
+			}
+
+			content, _ := json.Marshal(&request)
+			response, err := http.Post("https://test.wspay.biz/api/services/completion", "application/json", bytes.NewBuffer(content))
+			if err != nil {
+				c.AbortWithError(http.StatusInternalServerError, err)
+				return
+			}
+			if response.StatusCode == http.StatusOK {
+				transactionResponse := wspay.WsPayCompletionResponse{}
+				content, err := io.ReadAll(response.Body)
+				if err != nil {
+					c.AbortWithError(http.StatusInternalServerError, err)
+					return
+				}
+				if err := json.Unmarshal(content, &transactionResponse); err != nil {
+					c.AbortWithError(http.StatusInternalServerError, err)
+					return
+				} else {
+					log.Printf("Received transaction response: success=%s, errorMessage=%s, approvalCode=%s",
+						transactionResponse.ActionSuccess, transactionResponse.ErrorMessage, transactionResponse.ApprovalCode,
+					)
+					if wspay.CompareCompletionReturnSignature(transactionResponse.Signature, WsPayShopId, WsPayShopSecret, entry.ShoppingCartID, entry.STAN, transactionResponse.ActionSuccess, transactionResponse.ApprovalCode) != nil {
+						entry.TotalAmount = int64(amount * 100)
+						entry.State = state.StateCompleted
+						wspayService.Update(entry)
+					} else {
+						c.AbortWithError(http.StatusInternalServerError, errors.New("received invalid signature"))
+						return
+					}
+				}
+			} else {
+				c.AbortWithError(http.StatusInternalServerError, errors.New("received wrong status, expected 200 received "+strconv.FormatInt(int64(response.StatusCode), 10)))
+				return
+			}
+		}
+
+		c.Redirect(http.StatusSeeOther, "/wspay/info/"+id.String())
+	})
+	g.POST("cancel/:id", func(c *gin.Context) {
+		id := uuid.MustParse(c.Param("id"))
+		entry, err := wspayService.FetchById(id)
+		if err != nil {
+			c.AbortWithError(http.StatusNotFound, err)
+			return
+		}
+		if entry.State == state.StateAccepted {
+			var request = wspay.WsPayCompletionRequest{
+				Version:      "2.0",
+				WsPayOrderId: entry.ShoppingCartID,
+				ShopId:       entry.ShopID,
+				ApprovalCode: entry.ApprovalCode,
+				STAN:         entry.STAN,
+				Amount:       entry.TotalAmount,
+				Signature:    wspay.CalculateCompletionSignature(WsPayShopId, WsPayShopSecret, entry.ShoppingCartID, entry.STAN, entry.ApprovalCode, entry.TotalAmount),
+			}
+
+			content, _ := json.Marshal(&request)
+			response, err := http.Post("https://test.wspay.biz/api/services/void", "application/json", bytes.NewBuffer(content))
+			if err != nil {
+				c.AbortWithError(http.StatusInternalServerError, err)
+				return
+			}
+			if response.StatusCode == http.StatusOK {
+				transactionResponse := wspay.WsPayCompletionResponse{}
+				content, err := io.ReadAll(response.Body)
+				if err != nil {
+					c.AbortWithError(http.StatusInternalServerError, err)
+					return
+				}
+				if err := json.Unmarshal(content, &transactionResponse); err != nil {
+					c.AbortWithError(http.StatusInternalServerError, err)
+					return
+				} else {
+					log.Printf("Received transaction response: success=%s, errorMessage=%s, approvalCode=%s",
+						transactionResponse.ActionSuccess, transactionResponse.ErrorMessage, transactionResponse.ApprovalCode,
+					)
+					if wspay.CompareCompletionReturnSignature(transactionResponse.Signature, WsPayShopId, WsPayShopSecret, entry.ShoppingCartID, entry.STAN, transactionResponse.ActionSuccess, transactionResponse.ApprovalCode) != nil {
+						entry.State = state.StateCanceled
+						wspayService.Update(entry)
+					} else {
+						c.AbortWithError(http.StatusInternalServerError, errors.New("received invalid signature"))
+						return
+					}
+				}
+			} else {
+				c.AbortWithError(http.StatusInternalServerError, errors.New("received wrong status, expected 200 received "+strconv.FormatInt(int64(response.StatusCode), 10)))
+				return
+			}
+		}
+
+		c.Redirect(http.StatusSeeOther, "/wspay/info/"+id.String())
+	})
 	g.GET("success", func(c *gin.Context) {
 		response := wspay.WsPayFormReturn{}
 		if err := c.ShouldBind(&response); err != nil {
diff --git a/templates/wspay_info.gohtml b/templates/wspay_info.gohtml
index c6d3bdb..f20f233 100644
--- a/templates/wspay_info.gohtml
+++ b/templates/wspay_info.gohtml
@@ -45,5 +45,18 @@
 
         <tr><th>Stanje: </th><td>{{formatState .Entry.State}}</td></tr>
     </table>
+
+    {{if eq .Entry.State "accepted"}}
+        <form class="mb-3" method="post" action="/wspay/complete/{{.Entry.Id}}">
+            <div class="mb-3">
+                <label class="form-label" for="amount">Završi transakciju</label>
+                <input class="form-control" id="amount" required name="amount" type="number" value="{{formatCurrency2 .Entry.TotalAmount}}" step="0.01" min="0.01" max="{{formatCurrency2 .Entry.TotalAmount}}">
+            </div>
+            <button class="btn btn-primary" type="submit">Završi transakciju</button>
+        </form>
+        <form method="post" action="/wspay/cancel/{{.Entry.Id}}">
+            <button class="btn btn-primary" type="submit">Otkaži transakciju</button>
+        </form>
+    {{end}}
 </body>
 </html>
\ No newline at end of file
diff --git a/wspay/service.go b/wspay/service.go
index b878804..8fdcbfb 100644
--- a/wspay/service.go
+++ b/wspay/service.go
@@ -74,6 +74,27 @@ func CalculateFormSignature(shopId string, secret string, cartId string, amount
 	return hex.EncodeToString(hash.Sum(nil))
 }
 
+func CalculateCompletionSignature(shopId string, secret string, cartId string, stan string, approvalCode string, amount int64) string {
+	/**
+	Represents a signature created from string formatted from following values in a following order using
+	SHA512 algorithm:
+	ShopID
+	WsPayOrderId
+	SecretKey
+	STAN
+	SecretKey
+	ApprovalCode
+	SecretKey
+	Amount
+	SecretKey
+	WsPayOrderId
+	*/
+	signature := shopId + cartId + secret + stan + secret + approvalCode + secret + strconv.FormatInt(amount, 10) + secret + cartId
+	hash := sha512.New()
+	hash.Write([]byte(signature))
+	return hex.EncodeToString(hash.Sum(nil))
+}
+
 func CompareFormReturnSignature(signature string, shopId string, secret string, cartId string, success int, approvalCode string) error {
 	/**
 	Represents a signature created from string formatted from following values in a following order using
@@ -97,3 +118,26 @@ func CompareFormReturnSignature(signature string, shopId string, secret string,
 		return errors.New("signature mismatch")
 	}
 }
+
+func CompareCompletionReturnSignature(signature string, shopId string, secret string, stan string, actionSuccess string, approvalCode string, cartId string) error {
+	/**
+	Represents a signature created from string formatted from following values in a following order using
+	SHA512 algorithm:
+	ShopID
+	SecretKey
+	STAN
+	ActionSuccess
+	SecretKey
+	ApprovalCode
+	WsPayOrderId
+	Merchant should validate this signature to make sure that the request is originating from WSPayForm.
+	*/
+	calculatedSignature := shopId + secret + stan + actionSuccess + secret + approvalCode + cartId
+	hash := sha512.New()
+	hash.Write([]byte(calculatedSignature))
+	if hex.EncodeToString(hash.Sum(nil)) == signature {
+		return nil
+	} else {
+		return errors.New("signature mismatch")
+	}
+}
diff --git a/wspay/wspay.go b/wspay/wspay.go
index 1abf3d8..6596c69 100644
--- a/wspay/wspay.go
+++ b/wspay/wspay.go
@@ -102,7 +102,7 @@ type WsPayCompletionRequest struct {
 	ShopId       string
 	ApprovalCode string
 	STAN         string
-	Amount       string
+	Amount       int64
 	Signature    string
 }