API Integration Services for UK, US and EU Companies

Sources, flow direction, and acceptance ownership

For UK and EU businesses, an integration establishes the authoritative source for information across applications. A catalog may own product names, ERP owns available stock, and the carrier owns delivery status. They update at different times. Together with your team, we define each field’s source, direction, and acceptable delay before building bidirectional flows that could amplify contradictions.

Start with a data-flow map. Receiving, approving, shipping, and invoicing an order are separate events. Together with your team, we decide how cancellation or partial returns affect the chain and how corrections reach the destination. Automation moves exceptions requiring human decisions into a visible review queue.

Operational teams need to see failed transfers. A successful response alone does not prove correct processing. We review transaction IDs, destination document numbers, and reconciliation together. The same source ownership matters when developing an ecommerce website or adding connections to existing systems.

Marketplace catalog and order mapping

We review the channel’s seller API, account permissions, and current limits. Names such as Trendyol, Hepsiburada, N11, Amazon, or Pazarama do not establish that every data flow is available. Categories and required attributes vary. Each channel needs its own product mapping.

Catalog and stock mapping

We map stock codes, barcodes, and variant identities. Incorrect pack or color mappings can update the wrong listing. Make deleted products, closed listings, and rejected categories visible as different states. Your business approves assumptions for commissions, taxes, and rounding in channel-specific pricing.

Orders and channel status

The same external order may arrive repeatedly. We retain its identity so fetching it again does not create another order. Partial shipping, cancellation requests, and returns are not one completed flag. If a channel rejects invoice or tracking information, staff should see where processing stopped.

Existing integration platforms may be enough for standard catalogs. Custom connections suit decisions handled in your own software or specific warehouse and distributor rules. Support is confirmed only after reviewing documentation and test access. Scope is defined by permitted operations, not the system name.

Separate shipping labels from delivery status

Creating a shipment differs from handing a package to a carrier. A generated label does not prove delivery. Package count, weight, volumetric weight, address, and service type form the request. We retain external identity and creation results so reprocessing does not create a second shipment.

Access to Turkish carriers such as Yurtici Kargo, Aras Kargo, MNG Kargo, PTT Kargo, and Surat Kargo depends on the account and agreement. We review documentation and permissions first. Do not assume every carrier supports identical statuses or returns. We map carrier codes to business states; unknown codes must not silently mean delivered.

• We keep all tracking numbers for multi-package orders.
• We separate label cancellation from reprinting.
• We link returns to the original shipment.
• We route address errors to operational review.

Together with your team, we agree whether one failed record blocks a batch of labels. Created shipments can be compared with carrier acceptance at day end. Customer updates reflect the time and source of the event; delayed notifications should not reverse the current state.

Reconcile ERP documents and account records

We review official interfaces and licenses before connecting ERP. Versions and modules of Logo, Netsis, Nebim, DIA, AkinSoft, and Uyumsoft can offer different access. Listing a product name does not make every flow possible. On-premises systems may need secure middleware.

We map customer accounts, inventory codes, tax fields, and document types with finance and operations staff. Together with your team, we agree which account record is authoritative where duplicates exist. Similar names alone are not a reliable identity. We test dates, currencies, unit conversions, and rounding using sample documents.

We save the document ID when ERP accepts creation. Together with your team, we decide whether later corrections require a new document, revision, or reversing entry, using supported methods. Direct database writes are not a shortcut without vendor approval. Custom business software can handle specific operations while the authorized system retains official records.

Migration and daily operations need reconciliation. We show approved source orders not accepted by ERP, value differences, and unmatched accounts. Staff can correct and safely reprocess them instead of blindly retrying and risking duplicate documents.

From Turkish e-invoice submission to acceptance

Turkey’s e-Fatura and E-Arsiv integrations depend on the authorized provider’s API and document workflows. We validate taxpayer status, document type, tax fields, and recipient information before submission. Software must not guess decisions requiring finance approval. Current obligations and document scenarios need confirmation with your Turkish accounting adviser; technical integration is not legal advice or a promise of compliance in other markets.

Draft creation, submission, acceptance, and recipient delivery are separate states. Repeating submission while waiting can create duplicates. Associate document identity with provider results and query uncertain outcomes. The dashboard should show the waiting stage, not just success or failure.

Cancellation, objections, and partial returns follow the document type’s rules. Order status and legal invoice status remain distinct. Together with your team, we define document access, archiving, and visibility within your organization’s responsibilities. Acceptance compares values, taxes, currencies, and relationships using sample records.

Verify payment outcomes reliably

A browser or mobile app returning to a success screen does not prove payment. We match verified provider responses and transaction queries to the order. We check transaction identity, amount, currency, and relationship. We verify signed notifications and ensure repeated notifications have the same effect.

Bank payment gateways, iyzico, and PayTR require suitable merchant accounts, agreements, and permissions. International providers such as Stripe and PayPal need separate eligibility checks for the business’s country and account structure; they are not assumed available to every Turkish business. Scope installments, subscriptions, and refunds around actual provider capabilities.

Consider hosted or tokenized payment methods instead of storing card data. Together with your team, we define how 3D Secure results relate to order confirmation. After a timeout, investigate the first attempt before asking the customer to pay again. We show partial, repeated, and failed refunds separately.

Acceptance covers declined cards, abandoned authentication, late notifications, and incorrect amounts as well as successful payments. We test environments may not fully represent production. Limited live checks require authorized accounts and an approved scope.

Error handling for APIs, webhooks, and XML

REST APIs, webhooks, and files have different delivery behavior. API responses describe operations; webhooks can arrive late or repeatedly; XML is a snapshot at its creation time. Together with your team, we choose according to change frequency and available interfaces. Together with your team, we define transfer intervals and acceptable delays instead of using an unqualified real-time claim.

Retry rules differ by failure. Temporary connection problems and invalid product codes require different handling; invalid data needs correction before another attempt. Queues show transaction identity, attempts, and last errors. Respect rate limits and keep outages visible rather than hiding missing records.

XML checks cover completeness, encoding, date formats, and mapping. An empty or truncated file does not justify setting all stock to zero. Together with your team, we agree deletion and bulk-change rules separately. Undocumented internal systems may need custom API development, but access rights and data ownership remain prerequisites.