An app can request name, phone, location, payment data, and preferences within minutes of use. Each field, permission, and integration creates a responsibility for the company. This LGPD guide for apps shows how to transform data protection into part of the product, reducing legal risks, security failures, and friction that harm user trust.

For managers, LGPD should not be treated as a bureaucratic step before publishing to app stores. It affects business decisions, architecture, screen design, vendor hiring, customer service, and app evolution. The later these definitions enter the project, the higher the cost tends to be to fix processes and features.

What LGPD requires from an app

The General Data Protection Law regulates the processing of personal data carried out in Brazil. Processing is a broad concept: it includes collecting, storing, consulting, sharing, analyzing, modifying, and deleting information that identifies or could identify a person.

In a delivery app, for example, address, phone, and order history are personal data. In a healthcare solution, information about appointments or symptoms may be sensitive personal data, requiring even greater care. Even technical identifiers, such as IP, device ID, and location data, can fall under the law when associated with a user.

The central obligation is simple to understand and demanding to execute: the company must have a legitimate, clear, and informed purpose for processing each group of data. It is not enough to fill out a generic privacy policy or insert a checkbox in the registration. You must demonstrate why the data is necessary, how long it will be used, who will have access, and what measures protect that information.

Controller, processor, and vendors

In most cases, the company that owns the app acts as the controller, as it defines the objectives of data use. The software house, hosting platform, notification service, payment gateway, and analytics tools may act as processors or as independent controllers, depending on the activity performed.

This distinction must appear in contracts and operations. If a vendor processes data on behalf of the company, it must follow documented instructions, adopt security controls, and communicate incidents. If the company shares data with partners for their own purposes, the evaluation must be more careful, including transparency to the user and an appropriate legal basis.

Start with a data map of your app

The starting point for an LGPD-compliant project is to map the data flow. The team must know exactly which information enters the app, through which screens, APIs, and integrations it passes, where it is stored, and when it is deleted.

This work reveals common excesses. A scheduling app, for example, may need name, phone, and chosen time, but not necessarily birth date, background location, or access to phone contacts. Collecting less data reduces exposure, simplifies management, and improves privacy perception.

For each piece of data, record the purpose, legal basis, retention period, internal responsible parties, systems involved, and third parties who receive the information. The document does not need to be complex, but it must remain updated when new features, campaigns, or integrations are launched.

It is also worth separating essential data from optional data. If the user can complete a purchase without accepting promotional communications, that choice must be real. Conditioning the use of the service on an unnecessary permission is a practice that increases the risk of challenges and harms the experience.

Define the legal basis before coding

Consent is known to app users, but it is not the only legal basis provided for in LGPD. Depending on the case, processing may be necessary to execute a contract, comply with a legal obligation, prevent fraud, protect credit, or meet a legitimate interest, as long as the rights of the data subject are respected.

The correct legal basis depends on the purpose. To deliver an order, processing the customer's address may be necessary to execute the contract. To send personalized offers via notification, consent may be the safest alternative, especially when there is segmentation based on behavior. Payment data, on the other hand, requires additional attention, with secure integration and limited access.

When consent is used, it must be free, informed, and unambiguous. A clear screen explains what will be collected, for what purpose, and how the user can revoke authorization. Avoid hidden text, pre-checked options, or difficult-to-understand legal language. Unclear consent may not support processing in practice.

Data of children and adolescents

Apps aimed at children or that may attract this audience need a specific design. Processing must consider the best interest of the child and, in many situations, require specific and prominent consent from at least one guardian.

It is not enough to declare that the app is intended for adults if the flow, language, and features clearly appeal to minors. Age verification, permissions, advertising, and contact mechanisms must be evaluated from the product conception stage.

Privacy by design: technical decisions that prevent problems

Privacy by design means configuring the app to collect and expose the minimum necessary from the start. This approach should guide product, UX, development, and infrastructure, not just the legal team.

In practice, this includes requesting phone permissions when they are needed, not all during installation. An app that uses the camera to send a document should explain the reason before opening the request. If location is used to show nearby units, offer a manual search alternative for those who don't want to share their position.

Technical security is another pillar. Data in transit must be protected by secure connections, and stored data needs controls compatible with its criticality. Passwords cannot be stored in plain text. Tokens, API keys, and credentials should not be exposed in the app code. Administrative access must follow the principle of least privilege: each person accesses only what they need to work.

Other relevant measures include multi-factor authentication for internal areas, access logs, backup routines, vulnerability testing, dependency updates, and permission reviews in databases and cloud services. The exact solution varies depending on company size, number of users, and information sensitivity, but ignoring these layers is not a sustainable option.

Transparency in screens and privacy policy

The privacy policy is necessary, but should not carry the entire responsibility of informing alone. The user needs to receive explanations in the context in which they make a decision. If a screen asks for location, explain the benefit there. If the app enables notifications, make it clear whether they will be transactional, promotional, or both.

The policy should indicate, in accessible language, which data is processed, the purposes, the legal bases when applicable, the sharing, the rights of the data subject, contact channels, and security practices. It also needs to reflect how the app actually works. Copying a ready-made template and forgetting to update it after adding analytics or customer service tools is a recurring mistake.

Balance is important. Transparency does not mean dumping technical terms on every screen, as this causes abandonment. The best approach is to present short and objective messages during the journey, keeping complete details in a well-structured policy.

Meet user rights with a defined process

LGPD guarantees the data subject rights such as confirming the existence of processing, accessing data, correcting information, requesting anonymization or deletion in certain cases, revoking consent, and knowing with whom the data was shared.

The app needs to have a functional channel for these requests, in addition to internal processes to identify the user, locate information, and respond securely. In more mature products, some of this can be resolved in the user's own account, with data editing, information download, and preference management.

Not every deletion request requires immediate erasure. Data may need to be retained to comply with legal obligations, prevent fraud, or defend rights in legal proceedings. The company should explain the situation objectively, keep only what is necessary, and document the decision.

Prepare a plan for security incidents

No company is completely immune to failures, attacks, or operational errors. The difference lies in the ability to detect, contain, and respond quickly. An incident may involve unauthorized access to a database, API exposure, loss of a corporate device, or sending data to the wrong recipient.

The plan should define responsible parties, ways to record evidence, severity criteria, containment procedures, technical investigation, and communication. Depending on the risk to data subjects, there may be a need to notify the National Data Protection Authority and affected users.

Having this process before the problem occurs prevents rushed decisions. It also helps identify recurring causes, fix vulnerabilities, and reduce financial and reputational impacts.

LGPD guide for apps: transform compliance into value

An app aligned with LGPD tends to be more organized, secure, and easy to evolve. Data mapping improves visibility of integrations, minimization reduces storage costs, and a transparent experience reduces doubts in customer service. For businesses that sell, operate, or interact through mobile, trust is a direct part of conversion and retention.

The most efficient path is to include privacy from project discovery: validate which data supports each feature, design permissions with clarity, define contracts with vendors, and test controls before launch. In custom projects, Fox Grid can support this vision by connecting product strategy, secure development, and continuous technical monitoring.

Treating data with respect does not limit innovation. On the contrary, it creates a more reliable foundation to grow, integrate new services, and keep the user on your side when the app becomes essential to the business.