Cyber Security Services for Small Businesses
You don't need a security team. You need the right policies in the right places.
Practical cyber security for UK small businesses with 1 to 50 staff. Delivered remotely across the UK, with on-site support from our base in West London.
What does a cyber security service provider do?
A cyber security service provider sets up, manages and monitors the protection your business needs, so you don't have to hire a security team. Senri is a London-based provider for businesses with 1 to 50 staff: we secure your accounts, devices, email and data, train your team, and respond when something goes wrong.
Why businesses choose Senri
- A security-first IT team, so security is part of everyday IT, not an add-on
- We work with Sophos, Acronis and Bitdefender, and we're a member of Microsoft's partner programme
- Plain-English reports and no long contracts
What our cyber security services include
- Multi-factor authentication and Conditional Access on every account
- Endpoint protection on every laptop and desktop, managed and monitored
- Email security: anti-phishing, impersonation protection, SPF, DKIM and DMARC
- Device management and encryption, with remote wipe for lost devices
- Patching of operating systems and apps
- Backups that are tested, kept separate from Microsoft 365
- Security awareness training and practice phishing emails for staff
- Monitoring, alerting and incident response when something goes wrong
- Help preparing for Cyber Essentials
We secure your business using the same tools and frameworks that protect large enterprises, configured properly, managed actively, and explained in plain English. One of our clients had 979 phishing emails reaching staff inboxes every week and didn't know. A single policy deployment fixed it.
Good cyber security for a small business isn't about buying more software. It's about switching on the protection you already have, keeping it maintained, and having someone to call when something looks wrong.
Prevention
Email Security
Anti-phishing policies, spoof detection, DMARC/DKIM/SPF configuration, and impersonation protection. We recently deployed a single policy that caught 979 spoofed emails in the first week. Emails that had been reaching inboxes completely unfiltered.
Identity & Access
Multi-factor authentication, Conditional Access policies, legacy authentication blocking, and risky sign-in monitoring. The basics that stop most attacks before they start.
Data Loss Prevention
Policies preventing sensitive data from being shared externally (credit card numbers, personal data, confidential documents). Built on Microsoft Purview.
Detection & Response
Endpoint Security
Microsoft Defender for Endpoint: tamper protection, real-time threat detection, and automated investigation. Enterprise-grade protection on every device, managed and monitored.
Security Baseline & Hardening
Device security policies, attack surface reduction, and encryption enforcement via Intune. Your devices meet security standards before they touch your network.
Incident Response
When something goes wrong: immediate response. Isolate, investigate, remediate, report. We contain the damage and get you back to normal as fast as possible.
Cyber security packages for small businesses
Three clear levels of cybersecurity cover, built on the services above. Every business is different, so we tailor each package to your users, devices and requirements.
Essentials
For small teams that need the fundamentals in place and want to get ready for Cyber Essentials.
- MFA and Conditional Access for every account
- Defender for Business endpoint protection on all devices
- Email security with SPF, DKIM and DMARC configured
- Monthly patching of operating systems and apps
- Microsoft 365 backup
- Cyber Essentials readiness check
Protect
For growing businesses handling client data that need certification and a team that can spot a phish.
- Everything in Essentials
- Cyber Essentials certification support
- Anti-phishing and impersonation protection
- Phishing awareness training and simulations
- Device hardening and encryption via Intune
- Monitoring and alerting during business hours
Complete
For firms with sensitive data, regulated clients or supply chain requirements that need full cover.
- Everything in Protect
- Data loss prevention with Microsoft Purview
- 24/7 monitoring and alerting
- Incident response when something goes wrong
- Quarterly security reviews with a written report
- Support towards Cyber Essentials Plus
Not sure where you stand? Run our free email security checker to test your domain's SPF, DKIM and DMARC, see the cybersecurity tools we recommend, or read about our Cyber Essentials certification support.
What Our Clients Say
We brought Senri in to look at our IT setup and they found issues we didn't even know we had. They fixed everything, tightened up our security and now provide ongoing support. Wish we had found them sooner.
Clyde F.
Their team quickly identified the root causes of the problems, provided effective long-term solutions, and has been incredibly responsive whenever support is needed. Their professionalism, technical expertise, and proactive approach have given me complete peace of mind.
Sohail Yusuf
Frequently Asked Questions
Typically: multi-factor authentication, endpoint protection, email security, device management and encryption, patching, tested backups, staff security awareness training, monitoring and incident response. A good provider sets these up, keeps them maintained and reports to you in plain English.
Most small businesses don't need an in-house security team, but they do need someone responsible for security. Phishing and email account takeover hit small firms all the time, and a provider makes sure the protection you already pay for is switched on, maintained and watched.
An MSP runs your day-to-day IT; a cyber security provider focuses on protecting it. Senri does both, so security is built into how your IT is managed rather than handled by a separate company.
Yes. We check your setup against the Cyber Essentials requirements, fix the gaps and help you prepare the self-assessment. The certificate itself is issued by an accredited certification body.
We check your email domain configuration (SPF, DKIM, DMARC), identity and access policies, device security, data sharing settings, and endpoint protection. You get a clear report of what's working and what's exposed.
Most of our tooling is built on Microsoft Defender and Entra ID, so Microsoft 365 Business Premium is ideal. If you're on Google Workspace, we can still help with email security and device management using alternative tools.
Immediately. We isolate affected devices, investigate the breach, remediate the threat, and provide a full report. Our goal is containment within the first hour.
No. Security policies are rolled out in phases. We monitor for false positives before enforcing anything. Your team keeps working while protection ramps up in the background.
It depends on how many users and devices you have, what you already pay for in Microsoft 365, and whether you need certification or round-the-clock monitoring. We don't use one-size-fits-all pricing. After a short call and a free security review, we give you a personalised quote for the package that fits.
Every package covers the essentials: MFA and Conditional Access, endpoint protection with Microsoft Defender, email security (SPF, DKIM, DMARC), patching and backups. Higher tiers add Cyber Essentials certification support, phishing training and simulations, data loss prevention, 24/7 monitoring, incident response and quarterly security reviews.
Yes. Almost all cyber security work is delivered remotely, so we support small businesses across the UK. We're based in Brentford, West London, and provide on-site support across London and the South East when it's needed.
Get a free security review.
We'll check your email domain, access policies, and endpoint setup. We'll tell you exactly where you're exposed.