How to Choose Between SFTP and FTPS

Cyberattacks are here to stay, but threats are becoming more sophisticated. That’s why secure file transfers are essential in IT operations, especially for managed service providers (MSPs) who handle sensitive client data daily. Ensuring protected information sharing boils down to two protocols that often stand out: SFTP and FTPS.

Both the Secure File Transfer Protocol (SFTP) and the File Transfer Protocol Secure (FTPS) provide secure channels for data exchange. However, they differ in architecture, authentication, and firewall behavior. MSPs must consider these factors when choosing between the two file-sharing protocols, which could pose challenges for some.

In this guide, we will provide a practical framework for deciding between SFTP and FTPS, configuring them correctly, and building evidence-ready operations that simplify audits and reduce risks.

Best practices summary

Task 1: Decide with a simple matrix

📌 Use Case:

This task ensures that the chosen file transfer protocol matches business and network realities. It also promotes a policy-backed selection with documented reasons and exceptions.

Begin by knowing the following information:

• What firewall technology and configuration does your client use?
• What are your clients’ network constraints?
• What level of compliance do your clients face?
• What are the partner/legacy requirements?

After that, choosing between SFTP and FTPS depends on the gathered information. Here are the parameters you should consider:

• SFTP is a strong default when:
  • You need minimal firewall changes and a single listening port
  • Partners support SSH keys, and you want key-based or MFA-backed authentication.
  • You prefer chroot-style jails and straightforward folder isolation.
• FTPS is a strong default when:
  • Auditors or partners require TLS with X.509 certificates
  • You must integrate with legacy FTP tooling that already speaks FTPS
  • You can reserve and document a tight passive port range in firewalls

Document your protocol-choice per client profile as policy (see Task 5).

Task 2: Configure SFTP securely (Windows and appliances)

📌 Use Case:

This task ensures that you have a firewall-friendly SFTP service (one port), uses keys, limits exposure, and produces logs suitable for auditing, standing up SFTP with least privilege, and clear auditing.

If you choose SFTP, you need to configure it properly. Here are some actions you should take:

1. Set up and configure an SSH server, restrict it to a fixed port, disable password logins, and require SSH keys.
2. Create accounts for each partner or client with chrooted directories and minimal OS privileges.
3. Limit ciphers and MACs to modern options and disable SSH agent and port forwarding unless required.
4. Forward SSH auth logs and file activity to a central collector.

Task 3: Configure FTPS securely (Windows and appliances)

📌 Use Case:

This task ensures a certificate-centric FTPS service that integrates with audit requirements, supports legacy clients, and uses documented passive port rules to predict firewall rules.

Same with picking SFTP, if you choose FTPS, you must first ensure that an FTP server with SSL/TLS support is installed and enabled on the system (for example, IIS FTP on Windows or an appliance-based FTP service). Once the FTPS-capable service is in place, configure it securely by taking the following actions:

1. Install a trusted server certificate, disable unencrypted FTP access, and require TLS for control and data channels.
2. Define a narrow passive data port range and publish it to firewalls and partners.
3. Enforce TLS version minimums and modern cipher suites, prefer explicit FTPS, and require strong client authentication where possible.
4. Log control and data channel events, including usernames, source IPs, file transfer activity , and TLS session details.

Task 4: Harden access, keys, and certificates

📌 Use Case:

This task keeps authentication strong and maintainable by enforcing tight access control and swift recovery options.

Reducing the risk of threats is a core task in governing authentication and credentials, whether you choose SFTP or FTPS. Here are the actions you should take:

• Regular key and certificate rotations: Rotate SSH keys and FTPS client certificates on a schedule; expire stale credentials.
• Enforce least-privilege access: Use short-lived service accounts and scoped directories per partner.
• Implement connection restrictions: Apply IP allowlists and bandwidth limits for partners with strict SLAs.
• Define emergency procedures: Document emergency disable and revocation steps.

Task 5: Monitor, investigate, and prove compliance

📌 Use Case:

This task should turn file transfers into trustworthy records that promote operational visibility and audit-ready evidence.

Evidence of control is crucial when delivering a critical MSP service, such as operations involving SFTP and FTPS. Establishing a monitoring log that can withstand audits and investigations is important. Here are the tasks you need to accomplish:

• Call out anomalies: Alert on failed logins, sudden volume spikes, and transfers from unexpected regions.
• Cross-check logs: Correlate transfer logs with endpoint AV or EDR and DLP events for high-risk clients.
• Decide on record retention: Define, enforce, and document log retention policies that are mapped to client regulatory obligations, such as HIPAA or PCI DSS.
• Release reports regularly: Produce a monthly report that lists active partners, transfer counts, failures, and exceptions.

Rollout plan

As MSPs, you should have a standard and streamlined rollout plan to implement this operation across multiple partners or clients. Here’s what your rollout plan should cover:

1. Pilot with two partners on the chosen protocol, validate transfers and logging, and tune firewall rules.
2. Document the passive range or SFTP port, key, or certificate processes, and exception workflows.
3. Expand to remaining partners and schedule quarterly reviews of keys, certificates, and logs.

NinjaOne integrations

NinjaOne has tools and features that can help simplify the complexities of SFTP and FTPS implementation.

Choosing between and implementing SFTP and FTPS

Implementing secure file transfers across a managed environment is a cornerstone operation for MSPs. It begins with choosing between SFTP and FTPS, depending on which is the better default protocol for each client’s compliance requirements, network design, and authentication preferences.

Key takeaways:

• Pick SFTP for single port simplicity and key-based control, or FTPS for certificate-driven compliance and legacy tooling.
• Lock down ciphers, ports, and directories, and centralize logs before production use.
• Rotate keys and certificates on a schedule and document revocation.
• Report a small set of transfer and failure metrics monthly to prove control.

Following the outlined practices should not only help clients have a secure infrastructure when moving files but also ensure ongoing compliance, operational consistency, and verifiable control over every data transfer across their managed environments.

Related topics:

• What Is an FTP Server? Definition & Benefits
• What Is the MFT Protocol?
• The Importance of IoT Security: Tips for MSPs and IT Teams
• 28 Essential IT Automation Examples for Proactive MSP Monitoring, Alerting, and Remediation
• What Is an SSH Key?