Key takeaways
- Share work files in a company-owned group, not in personal chats or forwarded emails.
- C Chat encrypts files in transit with TLS and at rest with AES-256, using a key per organization.
- Attachments can be up to 25 MB each: PDFs, spreadsheets, images, contracts, plans.
- Invite clients or outside advisors as guests to a single group, not to your whole team.
- C Chat uses auditable encryption, not end-to-end encryption; group files are part of what admins can audit.
Contracts, invoices, ID copies, site plans, payroll spreadsheets: every business sends sensitive documents every day, and most of them travel through channels nobody chose on purpose. Email threads get forwarded, personal messaging apps end up holding client files on private phones, and USB sticks still change hands. A secure document exchange is less about one magic feature and more about where files go and who can see them.
Why document exchange fails on personal chat apps
The risks are usually about control, not about the encryption itself:
- Files live on personal accounts. When an employee leaves, the client’s documents stay in their chat history.
- Groups grow without anyone noticing. A client group created two years ago still includes a former contractor.
- Forwarding is frictionless. A document can travel from a work group to a family chat in two taps.
- No company record. When a client asks “did you receive the signed version?”, the answer is on someone’s phone.
How C Chat handles document exchange
C Chat keeps files inside your organization’s team and protects them the same way it protects messages:
- In transit: every upload and download travels over TLS.
- At rest: files are stored with AES-256 encryption at rest, using a key dedicated to your organization.
- Size: files up to 25 MB per attachment, plus photos, videos and voice notes.
- Access: only members of the group, plus owners and admins who can audit groups, can see what was shared there.
Read the technical detail in how photos, files and voice notes are protected.
C Chat uses auditable encryption. It is not end-to-end encrypted, and that is a deliberate trade-off: the business can audit and export group conversations, including the files shared in them, for compliance and disputes. Direct messages between two people are private and are not part of that audit.
Setting it up: groups, members and roles
Organize groups around the unit you need to keep confidential:
- One group per client, matter or deal. A real estate agency might use one per property transaction; an accounting firm one per client.
- Add only the staff working on it. Admins can add or remove members at any time.
- Invite outside parties as guests. Clients, notaries or advisors join that one group by invitation.
- Pin the key documents. Pin the latest signed contract or the current checklist so nobody uses an old version.
- Wrap up when the work ends. Remove guests and export the conversation if you need a copy for your files.
This pattern fits real estate teams, law firms and accounting firms, as well as distributed staff who share files from home; see secure messaging for remote teams.
Message formats and checklist
Make every document easy to identify months later:
[Document type] – [client / matter] – [version or date] What it is, what you need from the recipient, and by when.
Example: “Lease agreement – Unit 4B – v3 signed – please confirm receipt.”
Before sending a sensitive document, check:
- You are in the right group (the group name is visible at the top).
- Everyone in the group should see this file.
- The file name says what it is and which version.
- If personal data is involved, you are sharing only what the recipient needs.
- The recipient confirms with a reply or reaction.
Security and oversight
Security in a business context means two things at once: outsiders cannot read your files, and the company can show what was shared when it matters. C Chat covers both with per-organization AES-256 encryption at rest and group audit and export for owners and admins. The C Chat platform only accesses content to moderate reported messages or when legally required, and that access is logged.
For an overview of the whole model, visit the security page.
Getting started
Create one group for your most active client or project, invite the people involved and move the next document exchange there instead of email. C Chat is free for now within the plan limits, including 25 MB per attachment; see pricing and start at getcchat.com/c.
Frequently asked questions
Is it safe to send documents by chat?
It depends on the app and how you use it. Look for encryption in transit and at rest, company control over who is in each group, and the ability to remove people instantly. C Chat provides TLS and AES-256 with per-organization keys, and owners and admins control group membership.
What file types and sizes can I send in C Chat?
You can send files up to 25 MB per attachment, along with photos, videos and voice notes. For larger files, split them or share a link from the storage system your company already uses.
Is C Chat end-to-end encrypted?
No. C Chat uses auditable encryption: TLS in transit and AES-256 at rest with a key per organization, so team owners and admins can audit and export group conversations. Direct messages between people remain private. If you need end-to-end encryption, compare dedicated apps like Signal or Threema.
How do I share documents with a client without exposing my team?
Create a group for that client or matter and invite the client as a guest by link, QR code, WhatsApp, SMS or email. Guests only see the group they were invited to, not your other groups or members.