Payment Gateway Integration for Your Online Store or App: Stripe, PayPal, Redsys and Bizum

It depends on where you sell and how you charge. Redsys, your bank’s virtual POS in Spain, usually has negotiable fees and lets you take Bizum. Stripe offers more payment methods, subscriptions and international sales from a single integration. PayPal adds trust for customers who prefer not to enter their card. Many stores combine the bank POS with Stripe or PayPal, and we help you choose using your data.

With the Redsys module your bank provides or a paid one, configured with your virtual POS details (merchant number, terminal and key) and tested first in the Redsys test environment. What matters is that the order is confirmed by the bank’s signed notification and that refunds and Bizum work; if the module does not cover that, we extend it.

Yes. Bizum is enabled on your bank’s virtual POS (on Redsys) and appears as another payment method: the customer confirms the payment in their banking app. You request activation from your bank; we integrate and test it in your store. EquiMercado, for example, takes payments with Redsys and Bizum.

In a new store, payment gateways are part of the project: an online store starts at €8,000. For an existing store or application, we give you a fixed quote after the review, because it depends on the platform, the payment methods and whether there are subscriptions, automatic refunds or reconciliation with your ERP. Transaction fees are separate, under your contract with the bank or provider.

Yes: every business that accepts cards is subject to PCI DSS. But with a redirect gateway or the provider’s own hosted payment fields, the card number never reaches your server, and what is required of you shrinks considerably, usually to the shortest self-assessment questionnaire. Your bank or payment provider validates it. We build the integration so you fall into that case.

3-D Secure is the issuing bank’s check on a card payment (a code or a confirmation in its app). The European PSD2 directive requires strong customer authentication (SCA) for most online payments. With 3-D Secure 2 properly configured, many payments are authenticated without asking the customer for anything, and those that do require it happen without leaving the checkout.

Yes. The provider stores the card securely and your system keeps only a reference for later charges. We do it with Stripe and also with your bank’s POS where it supports it, with renewals, plan changes and retries of failed payments.

By linking every payment, fee and refund to its order number using the data the gateway returns, and matching it against the provider’s payouts or the bank’s credits. You know which orders make up each deposit and can pass it to your ERP or accounting software without manual matching.

Yes, with providers built for it, such as Stripe Connect: the provider verifies each seller, the customer pays once and the money is split, with the platform fee retained. It is a project with legal and tax implications that are worth reviewing before choosing a provider.

Yes. We set up the new gateway in parallel, test it in its test environment and switch it on once everything matches. Active subscriptions are the delicate part: depending on the provider, stored cards can be migrated or customers have to re-enter them, and we tell you before starting.