Alkateia
Family guides / Invitations and private access

How do temporary and QR code invitations work?

Understand codes, links, expiration, and approval. Explore Alkateia's screens and why a QR code alone does not guarantee an invitation's safety.

By AlkateiaUpdated September 20, 20263 min read

In this guide
  1. How does a QR code invitation work? The camera or reader interprets encoded content and opens the corresponding action. A QR code can represent an address or other data. It is a way to read information, not proof that the destination is trustworthy. DENSO WAVE, which created the technology, explains how it stores information in two dimensions. (DENSO WAVE)
  2. Can a QR code expire? The image itself does not disappear. The link or credential it represents may stop being accepted after a set time. An old screenshot can still be read by a camera but lead to an expired invitation. This differs from a scanning problem caused by focus or lighting.
  3. What is an invitation code? It is a sequence identifying an invitation and allowing the service to retrieve it. Entering a code and opening a link may lead to the same process, depending on the app. Handle both carefully: posting a code on an open network can share it beyond its intended recipients.
  4. Why do app invitations expire? Expiration limits how long an invitation can be used and reduces the availability of old credentials. It does not remove all risks: someone may receive a forwarded link while it is valid. A time limit works best alongside identity checks and access approval.
  5. How does it work in Alkateia? In Alkateia, invitations can be sent through a QR code, code, or unique link and expire in 10 minutes. After the person accepts, the parent, guardian, or administrator still needs to approve their entry. Accepting an invitation is not the same as final approval.
  6. Are QR code invitations safe? Safety depends on the destination, expiration, and who approves entry. Confirm that your relative actually sent the invitation and check the address before opening links. Never give a password or authentication code to someone claiming to need it to approve you. If unsure, request a new invitation through a known channel. (CERT.br)
  7. What should you do when an invitation expires? Ask the parent or guardian for a new invitation and accept within its validity period. Do not repeatedly try an old screenshot or post it asking others to “test” it. To organize approvals and understand closed groups, read about private group access control.

A temporary invitation gives time-limited permission to begin joining or linking an account. It may appear as a code, link, or QR code. The QR pattern represents information; validity and permissions are determined by the service receiving it.

How does a QR code invitation work? The camera or reader interprets encoded content and opens the corresponding action. A QR code can represent an address or other data. It is a way to read information, not proof that the destination is trustworthy. DENSO WAVE, which created the technology, explains how it stores information in two dimensions. (DENSO WAVE)

InvitationQR code, code, or link.
AcceptanceThe person responds before it expires.
ApprovalThe administrator confirms entry.
Alkateia family invitation acceptance screen with an expiration time
Accepting an invitation: entry still requires approval. Tap the image to enlarge.
Alkateia screen with a QR code and temporary family invitation code
Visual invitation example. Use a new invitation sent by your family. Tap the image to enlarge.

What should you do when an invitation expires? Ask the parent or guardian for a new invitation and accept within its validity period. Do not repeatedly try an old screenshot or post it asking others to “test” it. To organize approvals and understand closed groups, read about private group access control.

Sources and references

  1. DENSO WAVE — What is a QR Code?
  2. CERT.br — Social Networks Booklet

Sources accessed September 20, 2026. Informational content produced by Alkateia; information about the app describes its own features.