Exchange of Stock Balances Between 1C and 1C-Bitrix: Setup Guide

We configure the exchange of stock balances between 1C and 1C-Bitrix. Discrepancies between the site and the accounting system do not exceed a minute. A synchronization error is one of the most costly: one wrong XML warehouse identifier, and the site shows 0 instead of 15 units. The customer adds the product to the cart, but at checkout sees it is unavailable. We eliminate this gap. The average savings from automation are substantial due to reduced manual labor and fewer order cancellations. A single synchronization error can lead to significant losses. Our experience: over 7 years of integrations and 50+ projects. Thousands of orders are processed in real time daily. We guarantee 99.9% sync accuracy.

Why Warehouse-Level Stock Sync Matters

Data discrepancy between 1C and the site leads to lost orders and excessive purchases. One mismatch in the XML warehouse identifier — and balances do not distribute, ending up on an "unknown" warehouse. Example: 15 units in stock, site shows 0. We prevent this. On one project with 15,000 products, we configured sync every 10 minutes, reducing order cancellations due to stockouts by 3 times.

How Balances Are Transferred via CommerceML

According to the CommerceML specification, balances are included in the offers*.xml file inside the <QuantityInWarehouses> block:

<Offer>
  <Id>OFFER_GUID</Id>
  <QuantityInWarehouses>
    <QuantityInWarehouse>
      <WarehouseId>WAREHOUSE_GUID</WarehouseId>
      <WarehouseName>Main Warehouse</WarehouseName>
      <Quantity>15</Quantity>
    </QuantityInWarehouse>
  </QuantityInWarehouses>
  <Quantity>15</Quantity>
</Offer>

Bitrix updates balances per warehouse in the b_catalog_store_product table and the total balance in b_catalog_product. The total balance is an aggregate over all warehouses, used in catalog filters. We configure the exchange via CommerceML, accounting for all nuances.

How to Set Up Warehouses in Bitrix

Catalog → Warehouses → Warehouse settings:

• Create warehouses matching those in 1C.
• Assign each warehouse an XML identifier (field External code) — it must match the WarehouseId from the export.

Without matching XML identifiers, balances by warehouse will not distribute. The error is invisible until a manager detects the discrepancy. We guarantee correct configuration at this stage.

How to Configure Product Availability at Zero Stock

Catalog → Catalog settings → Zero stock. Three scenarios exist:

For stores with pre-order, implement logic via the element property PREORDER_AVAILABLE = Y. An event handler hides the "Buy" button and shows a pre-order form.

Why Reservation During Ordering Is Critical

To prevent stock going negative when multiple orders occur simultaneously, use these settings:

• Reservation moment: at order creation or upon payment confirmation.
• Reserve release: on order cancellation or after N days without payment.

The reserve is stored in b_sale_reserve_quantity and is considered when displaying available stock: available = stock - reserved. When transferring an order to 1C, ensure 1C understands "reserved quantity." Automating the exchange saves up to 40 hours of manager work per month.

How to Set Up Stock Exchange: Step-by-Step Guide

1. Create warehouses in 1C-Bitrix matching those in 1C. Assign each an XML identifier matching the WarehouseId from the export.
2. Configure the import of offers*.xml: in the admin section Settings → Data exchange, specify the file URL and schedule.
3. Verify identifier mapping: after the first import, open Catalog → Warehouses and ensure quantities match.
4. Set up reservation: in Shop settings → Reservation, choose the reservation moment.
5. Choose a zero-stock scenario: deactivate, "pre-order", or keep active.
6. Test the exchange: create an order, verify that stock decreased and the reserve appeared in 1C.

How Often to Update Stock Balances

Stock and prices are the most volatile data. Recommended settings:

Exchange via CommerceML with proper warehouse configuration runs 3 times faster than standard product import. For frequent exchange, use a separate thread only for offers*.xml.

What Is Included in Turnkey Stock Exchange Setup

• Audit of the current exchange and error identification.
• Creation and mapping of XML warehouse identifiers.
• Configuration of reservation and zero-stock scenarios.
• Setting import schedule per business type.
• Testing and result confirmation; training managers.

Turnkey setup includes all stages. Get a consultation on your project — we will analyze your current scheme and offer the optimal solution. Accurate stock balances increase conversion by 15–30%.

Setup Timelines

Basic setup of stock exchange with warehouse distribution takes 4–8 hours. With reservation, auto-activation, and separate scheduling — 1–2 days. Request an exchange audit — we will calculate exact timelines for your business.

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.