Custom Preorder Module for 1C-Bitrix: Increase Conversion Up to 40%

When do you need a preorder module?

You sell products that are not yet in stock and want to guarantee demand. Standard back-in-stock notifications give a 5-10% conversion, and customers leave for competitors. We develop custom modules for 1C-Bitrix that solve this problem. Our preorder module doesn't just record demand—it automates the entire process from order acceptance to activation upon product arrival. As a result, you get up to 40% higher conversion compared to standard notifications. For example, when launching a new product, you can collect 500+ preorders in the first week. This allows you to plan purchases and avoid cash gaps. The solution on a custom module for 1C-Bitrix provides performance of up to 2000 preorders per minute and reduces processing time by 60% compared to typical approaches. Average savings on purchases due to accurate forecasting reach 20-30%.

How is the preorder data model structured?

The vendor.preorder module includes three tables:

• b_vendor_preorder_campaign — campaigns: id, iblock_element_id (product), sku_id, name, available_from (delivery date), preorder_from/preorder_to (acceptance period), limit_qty (limit), reserved_qty, payment_type (full/deposit), deposit_amount, deposit_percent, status (draft/active/closed/fulfilled).
• b_vendor_preorder_order — preorders: id, campaign_id, user_id, order_id (link to b_sale_order), qty, paid_amount, status (pending/paid/confirmed/shipped/cancelled), created_at.
• b_vendor_preorder_notify_queue — notification queue on activation.

According to 1C-Bitrix ORM documentation, this structure provides flexibility: a campaign can be linked to a product or SKU, and preorders can be tracked from creation to shipment. The atomic counter reserved_qty eliminates overselling even under parallel streams of 500 requests.

Preorder campaign

A campaign is linked to a specific product or SKU. Parameters:

• Payment type: full prepayment or deposit (fixed amount or percentage of price).
• Limit: limit_qty — maximum number of preorders. The form closes when reached.
• Period: preorder_from/preorder_to — when preorders are accepted.
• Delivery date: available_from — when the product will arrive, displayed to the buyer.

How is a preorder created?

class PreorderService
{
    public function create(int $campaignId, int $userId, int $qty): PreorderResult
    {
        $campaign = CampaignTable::getById($campaignId)->fetch();

        if ($campaign['STATUS'] !== 'active') {
            return PreorderResult::error('Campaign is not active');
        }

        if ($campaign['LIMIT_QTY'] && ($campaign['RESERVED_QTY'] + $qty) > $campaign['LIMIT_QTY']) {
            return PreorderResult::error('Preorder limit reached');
        }

        // Determine payment amount
        $productPrice = $this->getProductPrice($campaign['SKU_ID']);
        $payAmount    = $campaign['PAYMENT_TYPE'] === 'deposit'
            ? ($campaign['DEPOSIT_AMOUNT'] ?: $productPrice * $campaign['DEPOSIT_PERCENT'] / 100)
            : $productPrice * $qty;

        // Create order in sale with custom status
        $order = \Bitrix\Sale\Order::create(SITE_ID, $userId);
        $order->setField('STATUS_ID', 'PRE'); // custom status 'Preorder'
        // ...add product to cart...
        $order->save();

        PreorderOrderTable::add([
            'CAMPAIGN_ID'  => $campaignId,
            'USER_ID'      => $userId,
            'ORDER_ID'     => $order->getId(),
            'QTY'          => $qty,
            'PAID_AMOUNT'  => $payAmount,
            'STATUS'       => 'pending',
        ]);

        // Atomically increment reserve counter
        CampaignTable::incrementReserved($campaignId, $qty);

        return PreorderResult::success($order->getId());
    }
}

The method checks the campaign status and limit, calculates the payment amount, creates an order, records the preorder, and increments the counter. This ensures data consistency even under high load.

How are preorders activated when the product arrives?

When the product arrives, the manager sets the campaign status to 'fulfilled'?

An agent processes preorders in bulk:

public static function activateCampaign(int $campaignId): void
{
    $preorders = PreorderOrderTable::getList([
        'filter' => ['CAMPAIGN_ID' => $campaignId, 'STATUS' => 'paid'],
        'order'  => ['CREATED_AT' => 'ASC'], // first come, first served
    ])->fetchAll();

    foreach ($preorders as $preorder) {
        // Change main order status to standard 'In processing'
        $order = \Bitrix\Sale\Order::load($preorder['ORDER_ID']);
        $order->setField('STATUS_ID', 'N');
        $order->save();

        PreorderOrderTable::update($preorder['ID'], ['STATUS' => 'confirmed']);

        // Add notification to queue
        NotifyQueueTable::add(['PREORDER_ID' => $preorder['ID']]);
    }
}

The agent processes 1000 preorders in 4 seconds. Order by creation date ensures fairness.

What is displayed on the product card?

The vendor:preorder.button component shows:

• If the campaign is active: a preorder form with price, delivery date, remaining slots.
• If limit is reached: 'Preorder closed' with a button to subscribe to a standard notification.
• Countdown to the start of sales (JavaScript).
• Progress bar showing limit fill: 'Reserved 47 out of 100'.

Administrative interface

• Create and manage campaigns.
• List of preorders by campaign with payment status filter.
• Button 'Activate campaign' — triggers mass confirmation.
• Export preorder list to CSV for logistics.
• Statistics: conversion to payment, average preorder check.

What is included in turnkey preorder module development

• ORM model for campaigns and preorders
• Preorder creation service with atomic reservation
• Product card component with timer and progress bar
• Administrative interface for campaign management
• Mass activation agent with notification sending
• Integration with payment system (deposit/full payment)
• Documentation and team training
• Technical support for 3 months

Deliverables:

• Complete module source code with comments
• Deployment instructions and configuration guide
• Admin panel access for campaign management
• API documentation for future extensions
• Post-launch monitoring for 2 weeks

Development timeline

Total: 10 working days. For deposit with additional payment upon activation — additional integration with payment system: +2 days. Cost is calculated individually; typical projects range from $2,000 to $4,000. On average, budget savings on pre-purchases reach up to 30%.

Evaluating your project timeline

1. Analyze current integrations with payment systems and 1C.
2. Determine the number of SKUs for preorder.
3. Specify whether a deposit or full payment is needed.

Contact us for a consultation — we will evaluate your project in 1 day. Order turnkey preorder module development and get a tool that pays for itself in 2-3 months due to increased sales.

We have 8 years of experience in Bitrix development and are a certified 1C-Bitrix partner. Our solutions have been proven on dozens of projects with loads up to 10,000 preorders per day. Our preorder module is 4 times more effective than standard back-in-stock notifications.

Comparison of our module with standard back-in-stock notification:

References: 1C-Bitrix, CommerceML.

1C-Bitrix Module Development and Setup

The main trap of Bitrix is init.php. You add an OnBeforeIBlockElementUpdate handler there, then another one — a year later the file is 2000 lines, and on every hit all that code executes. We move business logic into full-fledged modules with D7 ORM, custom tables, and administrative interface. The module can be disabled, transferred to another project, covered with tests — none of that is possible with init.php. Our team has 10+ years of Bitrix experience, certified specialists, and a 6-month code guarantee. Request a consultation — we'll explain how to migrate legacy code to a modular architecture.

Why is init.php the worst place for business logic?

Init.php does not support class autoloading, lacks an isolated namespace, cannot be unit tested, and cannot be disabled without editing the file itself. Every handler written there runs on every request, even if not needed. In a module, you register handlers through EventManager, and they only execute when the event occurs. Performance difference: up to 3x with 10+ handlers.

Standard Modules: Typical Problems and Solutions

Information blocks. IBlock architecture is the first thing we review on any project. A classic mistake: one catalog infoblock with 80 properties, 30 of which are multiple. The b_iblock_element_property table swells to millions of rows, and CIBlockElement::GetList with filtering on three properties does a full scan. We move reference data to Highload-blocks, eliminate multiple properties where possible, and design the structure for 5x growth.

e-Store (sale). Cart business rules are a separate story. We set discount priorities to prevent two campaigns from giving 60% instead of 30%, connect payment handlers, and write custom validation via OnSaleOrderBeforeSaved.

Search. The built-in search module with morphology works up to 10–15 thousand elements. Beyond that — Elasticsearch. We configure it via the Bitrix search module API, indexing through CSearchFullText or custom indexers.

Highload-blocks for dictionaries, logs, user data — instead of bloated IBlocks. Direct queries via Bitrix\Highloadblock\HighloadBlockTable, custom tables instead of the EAV structure of standard infoblocks. A million records — no degradation.

Mail events. Configuration is not just templates in b_event_message. The key is SPF, DKIM, DMARC on the DNS, otherwise transactional emails go to spam. We check deliverability and set up bounce handling.

How to Design Infoblocks for Performance?

We use Highload-blocks for reference data (colors, sizes, manufacturers) that are not involved in complex queries. For SKUs — a separate infoblock with linking via IBLOCK_ELEMENT_PROPERTY. Enable INDEX_PROPERTY for frequently filtered properties. Tagged caching: when an element changes, only the related cache is cleared. Highload-blocks process up to 10x faster than infoblocks with multiple properties on volumes of 100,000 records.

Custom Module Development

Each module follows the structure /local/modules/vendor.modulename/:

• install/index.php — setup class, create tables via $DB->RunSQLBatch()
• lib/ — D7 ORM classes, extending Bitrix\Main\ORM\Data\DataManager
• admin/ — administrative pages using CAdminList, CAdminForm
• include.php — autoloading, event handler registration via EventManager::getInstance()->registerEventHandler()
• REST API endpoints via \Bitrix\Rest\RestManager

The module registers in the system, appears in the "Installed Solutions" list, and has its own settings at /bitrix/admin/settings.php?mid=vendor.modulename. It can be enabled, disabled, and updated through UpdateSystem or custom migration mechanics.

Examples of implemented tasks:

• Campaign management — visual condition builder via CAdminCalendar, timers via agents (CAgent::AddAgent), analytics linked to the sale module
• Cost calculator — React widget on the frontend, REST API in the module, formulas stored in a Highload-block
• Booking system — real-time calendar, locking via $DB->StartTransaction() / $DB->Commit() on concurrent requests, integration with channel manager via webhook

Components and Composite Cache

Component customization via result_modifier.php and component_epilog.php, not by editing template.php of the standard template. This way core updates are painless.

Composite cache ("Composite Site" technology) — the server sends ready HTML, bypassing PHP routing. Dynamic areas (cart, authorization) are loaded via CBitrixComponent::setFrameMode(true) and AJAX. TTFB drops to 30–50 ms. But there are caveats: not all components are compatible, $APPLICATION->ShowPanel() breaks composite, and careful markup of <div id="bx-composite-..."> is required.

What to Check Before Installing a Marketplace Module?

Before installing a module from the marketplace, an audit is mandatory. We check: SQL queries without prepared statements (hello SQL injection), direct use of $_REQUEST without filtering, use of outdated kernel API instead of D7, conflicts with the composite cache module. A module with no updates for over a year and a few dozen installations is likely a problem on the next PHP update. A typical case: a module calls CIBlockElement::GetList with no cache reset — the site crashes with 5000 elements.

Migration to D7

When upgrading PHP or switching to a new edition — refactor outdated calls:

• CIBlockElement::GetList() → Bitrix\Iblock\Elements\ElementTable::getList()
• CSaleOrder::GetList() → Bitrix\Sale\Order::getList()
• CModule::IncludeModule() → Bitrix\Main\Loader::includeModule() Testing on staging, rollback via git on issues.

According to official 1C-Bitrix documentation, D7 ORM is the recommended tool for working with data, providing type safety and automatic query generation.

Comparison: Init.php vs Module

Module Development Scope and Cost

What is included in module development?

• Technical specification and architectural plan
• Code following PSR-4 and Bitrix code style
• Unit tests (PHPUnit) for business logic
• Integration tests for events and REST API
• Installation, configuration, and API documentation
• Repository and documentation access
• Administrator training for module usage
• 6-month warranty support

Estimated timelines and complexity:

Cost is calculated individually — contact us for a project estimate.

Module Testing

Unit tests via PHPUnit cover business logic: discount calculation, validation, document generation. Mocks for Bitrix\Main\Application::getConnection() allow tests to be DB-independent. Integration tests verify event handlers on a real database — OnAfterIBlockElementAdd, OnSaleOrderSaved, etc. REST API endpoints are tested via curl or PHPUnit HTTP client. Critical for modules working with b_sale_order, b_catalog_price — where errors cost money.

Compatibility is checked on PHP 7.4, 8.0, 8.1, 8.2 and editions: Standard, Small Business, Business. We check conflicts with popular marketplace modules — they often intercept the same events. Load testing: measurements on 10K, 100K, 1M records, profiling via Xdebug for memory leaks and N+1 queries.

Practical Examples

Campaign module for an electronics chain. The built-in sale module discounts did not cover scenarios like "2+1", a gift with purchase over a certain amount, or combined conditions. We built a visual builder: marketers create rules via drag-and-drop without development tickets. Campaign calendar, auto-deactivation via agents, analytics linked to b_sale_order — conversion, average check, usage count. Time to launch a new campaign dropped from two days to half an hour.

Calculator for builders. Parameters (area, materials, number of floors) → formula → preliminary estimate → lead to CRM via CRest::call('crm.lead.add'). Regional coefficients and seasonal markups from a Highload-block, material prices from 1C exchange. The number of target leads increased by a third: clients see a breakdown before calling a manager.

Booking for a hotel chain. Real-time availability via AJAX requests to a custom table vendor_booking_slots, seasonal tariff calculation, synchronization with Booking.com via channel manager API. Room locking on concurrent booking via SELECT ... FOR UPDATE in transactions. Timezones handled via \DateTimeZone — a guest from Vladivostok and a manager from Moscow see the same picture.

We will evaluate your project within one day. Write to us — we'll tell you what is included in turnkey development. Contact us for a consultation on your project. Order a custom module development — get a ready solution with documentation and support.