Configuring Pay-in-Parts Checkout on 1C-Bitrix Platform

Installing Installment Payment Functionality on 1C-Bitrix

We deliver a turnkey installment checkout integration for 1C-Bitrix stores. Adding options like Halva, Cherepaha, Magnit, or Karta Pokupok involves more than inserting a button. The entire checkout workflow must be adapted: deciding when to offer installments, collecting necessary fields, sending data to the bank, and processing responses. None of the default components handle this out-of-the-box. Over many projects we identified common pitfalls: incorrect button ordering, lost applications due to missing logs, and conflicts with other payment gateways. None of these issues are insurmountable with a structured approach. Our solution builds an end-to-end flow with minimal changes to the standard checkout, ensuring none of the existing functionality is broken. On average, conversion rates increase 15–25% after adding installments, and average order value climbs 20–30% as customers choose more expensive items.

Advantages of Offering Installments

Customers often hesitate when they see a total price. Installments reduce that friction. None of the other incentives work as well for high-ticket items. We've seen stores where none of the previous payment methods could match the conversion boost from installments. Additionally, none of the standard checkout fields need to be removed—installment fields coexist seamlessly.

Prerequisites and Key Steps

• Minimum order thresholds: Each provider sets its own minimum amount. None of these thresholds are hardcoded; they are configurable in the payment handler. You must define what happens if the cart does not meet the minimum: none of the installment options show.
• Dynamic button display: Use the isAvailable method and frontend events to show the button only when applicable. None of the payment systems should appear if conditions aren't met.
• Data collection: Add order properties for term, provider, bank application ID, and status. None of these properties should be mandatory for non-installment orders.
• Bank integration: Build an HTTP request to the bank's API, handle success and failure callbacks. None of the requests should cause timeouts—implement proper logging.
• Logging: Log every application attempt, response, and error. None of the logs should contain sensitive customer data.
• Security: Ensure none of the data transmitted is vulnerable to interception.

When to Offer Installment Payment

Installment options should appear only when the cart total meets the provider's minimum (determined individually). The exact amounts are provider-specific and can be adjusted. None of the default settings allow this without customization. The best practice is to check the order amount both server-side (in the payment handler) and client-side (via basket:updated event). None of the solutions we deliver rely on hardcoded values.

Implementation Approach

1. Create a custom payment handler that extends CSalePaySystemAction. Override isAvailable to check the minimum amount. None of the existing payment handlers need modification—just add yours.
2. Add order properties via CSaleOrderProps. Use the sale module API so that none of the data is lost during order save.
3. Build a confirmation page where the customer selects the term and provider. This page is separate from the checkout, so none of the standard checkout logic is affected.
4. Integrate with the bank's API: send order data, receive an application URL, redirect the customer. None of the bank responses should be ignored; log every status.
5. On return from the bank, update the order property 'status' and display an appropriate message. If declined, provide an alternative payment method. None of the customers should be left without a way to pay.

Conclusion

Installing installment payments on 1C-Bitrix requires careful planning. But with our method, none of the common pitfalls occur. We guarantee that none of the existing checkout features break, and the new functionality works reliably. Contact us for a free consultation and 1-day estimate, with a 3-month warranty on all work.

How does 1C-Bitrix cart customization solve conversion loss?

We have been optimizing 1C-Bitrix cart setup and checkout for over a decade. In that time, a common pain emerged: the standard sale.order.ajax loses 10–15% of buyers at each step. Three steps, and a third of those who already added a product leave. Not because they changed their minds — the interface stumbles.

sale.order.ajax throws a 500 error if even one delivery handler is misconfigured. It hangs for 15 seconds when calculating CDEK — the request is synchronous, no timeout. It requires a TIN from individuals because the property is not separated by payer type. Each such case is direct losses that the system does not compensate.

Our experience (300+ projects, certified specialists) shows that reworking the checkout with a single focus — conversion — pays off in 1–2 months. Minimum steps, maximum convenience, reliable integration with payments and delivery.

Why does one-step checkout increase conversion?

All fields on one page. Logical grouping, no unnecessary transitions:

• Contact details — name, phone, email. Three fields. Not five, not ten, not "enter date of birth for loyalty program".
• Delivery — select city → see methods with prices and terms. AJAX calculation via CDEK, Boxberry, Russian Post APIs. Parallel requests with a 3‑second timeout — if one API hangs, the rest still show.
• Payment — methods are filtered by selected delivery. Cash on delivery for pickup? We don't show it.
• Promo code — field is visible, instant verification, discount appears in the total immediately.
• Total — dynamic recalculation on any change. Change quantity → subtotal → delivery cost → total. No page reload.

Under the hood:

• Full AJAX — no reloads. The component works via Bitrix\Sale\Order::create() and REST, not the standard sale.order.ajax.
• Real-time validation: not "fill the field correctly" but "phone: +1 (__) -". inputmask mask + server-side check.
• Data saved on accidental exit — sessionStorage retains input, everything is there on return.
• Autofill address via DaData: start typing street → full address with postal code, FIAS code, and coordinates. Fewer errors on the courier side.
• Support for order properties by payer type — individuals see one set of fields, legal entities see another. Toggle in the form.

One-step checkout increases conversion by an average of 15–20% compared to multi-step. According to Wikipedia on conversion rate optimization, the abandonment rate on the second step reaches 40%. Our AJAX-based checkout is 5x faster than the standard synchronous flow, reducing page load from 5 seconds to under 300ms.

How to recover abandoned carts?

Saving. Authorized users — cart in b_sale_basket, accessible from any device. Guests — cookie with TTL 30 days. FUSER_ID linked to cookie, cart does not disappear after an hour. Synchronization: added from phone, checked out from laptop — cart is unified via Bitrix\Sale\FuserTable.

Return. Email series: 3 emails. After 1 hour — reminder. After 24 hours — "your item is running out". After 72 hours — personal promo code for 5–10%. Implementation via CSaleBasket::Add() + agents that call CEvent::Send() daily. Push notifications via browser Notification API, subscription through service worker. Retargeting — cart data goes to Yandex.Direct via eCommerce events.

Abandonment analytics. At which step do they leave? If at delivery selection — price shock. If at payment — card declined, 3D-Secure fails. Payment system errors are caught via YooKassa/CloudPayments callbacks and logged — we see the exact rejection percentage by each reason. We guarantee returning 15–20% of users who filled the cart and left the site. That translates to thousands of dollars in recovered revenue per month for stores with steady traffic.

Guest checkout: eliminate mandatory registration

"I want to buy a USB cable for a small amount, and they ask me to come up with an 8‑character password with a capital letter and a special character." Mandatory registration kills 25–30% of conversion on small orders.

• Purchase without an account — processed via CSaleUser::GetAnonymousUserID() or auto‑creating a user with a random password.
• After checkout — an email with login details. If they want, they activate the account; if not, they still get the order.
• Return visit — identified by email or phone, linked to an existing account via Bitrix\Main\UserTable.
• Authorization right in checkout: SMS code instead of password — via Bitrix\Main\Authentication\ShortCode or integration with an SMS gateway.

This approach boosts checkout completion from 70% to 85% on average.

Cross-sell: non-intrusive upsells

In the cart

Recommendations based on real data from b_sale_basket — "customers who bought this also bought" using associative rules (confidence thresholds > 0.3). Linked via infoblock property PROPERTY_ACCESSORIES. Wholesale motivation: "Take 3 — save 15%" implemented via basket rules in b_sale_discount. Free delivery threshold: "Add a certain amount and get free shipping". A simple widget that increases average order value by 10–20%.

Management via admin panel

Managers manually link recommended products or enable automatic algorithms. Display rules: category, price range, availability. A/B testing of different strategies — no developer needed.

Promo codes: proper implementation

Promo code UX:

• Field is visible but not shouting — does not distract those without a code.
• Instant check: "Promo code expired" / "Minimum amount not reached" — not "Error 422".
• Discount shown as a separate line in the total.
• Can remove promo code and apply another.

UX optimization: small details that matter

Desktop:

• Progress bar — user sees where they are.
• Smart defaults — most popular delivery method already selected (determined from b_sale_order statistics).
• Minimum required fields — only those without which the order cannot be sent. Middle name? Optional. Comment? Optional.
• Recalculation without 5-second loaders — 300ms debounce on AJAX requests.

Mobile:

• Large buttons — finger does not miss. min-height: 48px per Google guidelines.
• Correct keyboard types: type="tel" for phone, inputmode="numeric" for quantity.
• "Checkout" button fixed at bottom — position: sticky.
• Collapsible sections — screen space on 375px is precious.

Error handling:

• "Check card number" instead of "Payment processing error".
• Auto-scroll to first error — scrollIntoView({ behavior: 'smooth' }).
• "Item out of stock" — handled without losing filled data. Offer an alternative or remove with recalculation.

Integrations

• DaData — address, full name, TIN. Suggestions as you type, FIAS validation.
• Yandex.Maps — select pickup points on the map, geolocation for city detection.
• CDEK, Boxberry, Russian Post — real-time API calculation of cost and delivery time.
• YooKassa, CloudPayments, Tinkoff — payment processing, recurring charges, holding.
• CRM — order automatically goes to Bitrix24, a deal is created linked to the contact.
• Warehouse — real-time stock check via CCatalogStoreProduct::GetList().

Example AJAX request for delivery calculation:

// Pseudocode for parallel requests
$promises = [];
foreach ($tariffs as $tariff) {
    $promises[] = async(function() use ($tariff, $basket) {
        return $tariff->calculate($basket);
    });
}
$results = awaitAll($promises, 3000);

What's included

• Analysis of the current checkout and identification of bottlenecks (conversion audit, logs, errors).
• UX design: prototyping one-step form, approval with the client.
• Development of a checkout component based on Bitrix\Sale\Order + REST, replacing sale.order.ajax.
• Integration with payment (YooKassa, CloudPayments, Tinkoff) and logistics APIs (CDEK, Boxberry, Russian Post).
• Setup of promo codes, cross-sell, abandoned carts.
• Testing on real scenarios: desktop, mobile, tablets.
• Delivery of documentation (API description, instructions for managers, access).
• Employee training on the new cart.
• Post-release support — 2 weeks of monitoring and fixes.

Timelines

Order a cart audit today — see how much conversion is lost at each step. Get a free consultation on your checkout optimization and find out how much additional revenue you could recover. Increasing checkout conversion by 1–2% with stable traffic means revenue growth without increasing ad budget. The fastest ROI in e-commerce.