diff --git a/modules/client/back/methods/tpv-transaction/confirm.js b/modules/client/back/methods/tpv-transaction/confirm.js
index bec818bc9..b7d0c736f 100644
--- a/modules/client/back/methods/tpv-transaction/confirm.js
+++ b/modules/client/back/methods/tpv-transaction/confirm.js
@@ -1,4 +1,3 @@
-const crypto = require('crypto');
 const UserError = require('vn-loopback/util/user-error');
 const base64url = require('base64url');
 
@@ -21,19 +20,12 @@ module.exports = Self => {
                 required: true,
             }
         ],
-        returns: {
-            type: 'Boolean',
-            root: true
-        },
         http: {
             path: `/confirm`,
             verb: 'POST'
         }
     });
 
-    /*
-     * Source: https://github.com/santiperez/node-redsys-api
-     */
     Self.confirm = async(signatureVersion, merchantParameters, signature) => {
         const $ = Self.app.models;
 
@@ -56,19 +48,11 @@ module.exports = Self => {
             fields: ['id', 'secretKey']
         });
 
-        const secretKey = Buffer.from(merchant.secretKey, 'base64');
-        const iv = Buffer.alloc(8, 0);
-
-        const cipher = crypto.createCipheriv('des-ede3-cbc', secretKey, iv);
-        cipher.setAutoPadding(false);
-        const orderKey = Buffer.concat([
-            cipher.update(zeroPad(orderId, 8)),
-            cipher.final()
-        ]);
-
-        const base64hmac = crypto.createHmac('sha256', orderKey)
-            .update(merchantParameters)
-            .digest('base64');
+        const base64hmac = Self.createSignature(
+            orderId,
+            merchant.secretKey,
+            merchantParameters
+        );
 
         if (base64hmac !== base64url.toBase64(signature))
             throw new UserError('Invalid signature');
@@ -81,14 +65,6 @@ module.exports = Self => {
                 params['Ds_Currency'],
                 params['Ds_Response'],
                 params['Ds_ErrorCode']
-            ]
-        );
-        return true;
+            ]);
     };
-
-    function zeroPad(buf, blocksize) {
-        const buffer = typeof buf === 'string' ? Buffer.from(buf, 'utf8') : buf;
-        const pad = Buffer.alloc((blocksize - (buffer.length % blocksize)) % blocksize, 0);
-        return Buffer.concat([buffer, pad]);
-    }
 };
diff --git a/modules/client/back/methods/tpv-transaction/end.js b/modules/client/back/methods/tpv-transaction/end.js
new file mode 100644
index 000000000..5a757aa48
--- /dev/null
+++ b/modules/client/back/methods/tpv-transaction/end.js
@@ -0,0 +1,39 @@
+const UserError = require('vn-loopback/util/user-error');
+
+module.exports = Self => {
+    Self.remoteMethodCtx('end', {
+        description: 'Ends electronic payment transaction',
+        accessType: 'WRITE',
+        accepts: [
+            {
+                arg: 'orderId',
+                type: 'string',
+                required: true,
+            }, {
+                arg: 'status',
+                type: 'string',
+                required: true,
+            }
+        ],
+        http: {
+            path: `/end`,
+            verb: 'POST'
+        }
+    });
+
+    Self.end = async(ctx, orderId, status) => {
+        const userId = ctx.req.accessToken.userId;
+        const transaction = await Self.findById(orderId, {
+            fields: ['id', 'clientFk']
+        });
+
+        if (transaction?.clientFk != userId)
+            throw new UserError('Transaction not owned by user');
+
+        await Self.rawSql(
+            'CALL hedera.tpvTransaction_end(?, ?)', [
+                orderId,
+                status
+            ]);
+    };
+};
diff --git a/modules/client/back/methods/tpv-transaction/start.js b/modules/client/back/methods/tpv-transaction/start.js
new file mode 100644
index 000000000..ea6ed05eb
--- /dev/null
+++ b/modules/client/back/methods/tpv-transaction/start.js
@@ -0,0 +1,85 @@
+const UserError = require('vn-loopback/util/user-error');
+
+module.exports = Self => {
+    Self.remoteMethodCtx('start', {
+        description: 'Starts electronic payment transaction',
+        accessType: 'WRITE',
+        accepts: [
+            {
+                arg: 'amount',
+                type: 'Number',
+                required: true,
+            }, {
+                arg: 'companyId',
+                type: 'Number',
+                required: false,
+            }, {
+                arg: 'urlOk',
+                type: 'String',
+                required: false,
+            }, {
+                arg: 'urlKo',
+                type: 'String',
+                required: false,
+            }
+        ],
+        returns: {
+            type: 'Object',
+            root: true
+        },
+        http: {
+            path: `/start`,
+            verb: 'POST'
+        }
+    });
+
+    Self.start = async(ctx, amount, companyId, urlOk, urlKo) => {
+        const userId = ctx.req.accessToken.userId;
+        const [[row]] = await Self.rawSql(
+            'CALL hedera.tpvTransaction_start(?, ?, ?)', [
+                amount,
+                companyId,
+                userId
+            ]);
+
+        if (!row)
+            throw new UserError('Transaction error');
+
+        const orderId = row.transactionId.padStart(12, '0');
+        const merchantUrl = row.merchantUrl ? row.merchantUrl : '';
+        urlOk = urlOk ? urlOk.replace('_transactionId_', orderId) : '';
+        urlKo = urlKo ? urlKo.replace('_transactionId_', orderId) : '';
+
+        const params = {
+            'Ds_Merchant_Amount': amount,
+            'Ds_Merchant_Order': orderId,
+            'Ds_Merchant_MerchantCode': row.merchant,
+            'Ds_Merchant_Currency': row.currency,
+            'Ds_Merchant_TransactionType': row.transactionType,
+            'Ds_Merchant_Terminal': row.terminal,
+            'Ds_Merchant_MerchantURL': merchantUrl,
+            'Ds_Merchant_UrlOK': urlOk,
+            'Ds_Merchant_UrlKO': urlKo
+        };
+        for (const param in params)
+            params[param] = encodeURIComponent(params[param]);
+
+        const json = JSON.stringify(params);
+        const merchantParameters = Buffer.from(json).toString('base64');
+
+        const signature = Self.createSignature(
+            orderId,
+            row.secretKey,
+            merchantParameters
+        );
+
+        return {
+            url: row.url,
+            postValues: {
+                'Ds_SignatureVersion': 'HMAC_SHA256_V1',
+                'Ds_MerchantParameters': merchantParameters,
+                'Ds_Signature': signature
+            }
+        };
+    };
+};
diff --git a/modules/client/back/models/tpv-transaction.js b/modules/client/back/models/tpv-transaction.js
index b511ae52e..eb9dd7d6c 100644
--- a/modules/client/back/models/tpv-transaction.js
+++ b/modules/client/back/models/tpv-transaction.js
@@ -1,3 +1,29 @@
+const crypto = require('crypto');
+
 module.exports = Self => {
     require('../methods/tpv-transaction/confirm')(Self);
+    require('../methods/tpv-transaction/start')(Self);
+    require('../methods/tpv-transaction/end')(Self);
+
+    Self.createSignature = function(orderId, secretKey, merchantParameters) {
+        secretKey = Buffer.from(secretKey, 'base64');
+        const iv = Buffer.alloc(8, 0);
+
+        const cipher = crypto.createCipheriv('des-ede3-cbc', secretKey, iv);
+        cipher.setAutoPadding(false);
+        const orderKey = Buffer.concat([
+            cipher.update(zeroPad(orderId, 8)),
+            cipher.final()
+        ]);
+
+        return crypto.createHmac('sha256', orderKey)
+            .update(merchantParameters)
+            .digest('base64');
+    };
+
+    function zeroPad(buf, blocksize) {
+        const buffer = typeof buf === 'string' ? Buffer.from(buf, 'utf8') : buf;
+        const pad = Buffer.alloc((blocksize - (buffer.length % blocksize)) % blocksize, 0);
+        return Buffer.concat([buffer, pad]);
+    }
 };