The MSP vs MSSP question turns up the moment an organisation decides its IT matters too much to run on goodwill and spare evenings. The short answer is this. A managed service provider runs your IT. A managed security service provider defends it. One keeps things working, the other watches for the people trying to break them.
That distinction is real. It is also blurrier than most comparison articles admit, and in the UK it is about to carry far less legal weight than you would expect. This guide covers what each one actually does, where the two overlap, which your organisation needs, and what to ask before signing with either.
In the MSP vs MSSP comparison, the letters on the contract matter far less than the scope inside it. Two providers can both call themselves an MSSP and sell completely different things, and UK law is about to treat both of them identically anyway.
What an MSP Actually Does
A managed service provider takes ongoing responsibility for your IT under contract, usually for a fixed monthly fee per user or per device. The work is operational. A service desk your staff can ring, monitoring and patching, servers and networks and cloud platforms, backup and recovery, procurement and device lifecycle, with some level of reporting and planning on top.
The defining feature is continuity rather than capability. An MSP is not called in when something breaks. It is already there, already watching, already accountable. That is the whole difference between a break-fix contractor and a managed service, and it is why the model exists at all.
Most MSPs do security work too, and it is worth being precise about that because the marketing often is not. Patching is security work. So is firewall management, enforcing multi-factor authentication, controlling who holds admin rights, and making sure backups actually restore. What a general MSP usually does not have is a team whose only job is to watch for an attacker who is already inside.
What an MSSP Actually Does
A managed security service provider is the specialist. Its product is detection and response rather than availability. At the centre of it sits a security operations centre: people and tooling watching logs and telemetry from across your estate, looking for the patterns that mean an intruder rather than a fault.
Typical scope runs to monitoring and triage, managed detection and response, vulnerability management, email and phishing defence, penetration testing, and incident response when something is confirmed. Many add governance work on top, including policy, risk registers, audit support and virtual CISO time.
An MSSP will not normally fix a broken laptop, run your procurement or migrate your email. That is not a shortcoming, it is the division of labour. You are buying depth instead of breadth, and in most cases you are buying it on top of something else rather than instead of it.
One disclosure before going further. Transputec provides both, so we have a view. The sections below set out the trade-offs either way, including the cases where buying from two separate firms is the better answer.
Not sure which one you are actually buying?
Transputec runs the IT and the security operations under one contract, from a London service desk and a London SOC. Talk to our team about what your estate actually needs.
Book a consultationMSP vs MSSP: The Differences That Actually Matter
Most MSP vs MSSP comparisons produce a tidy table and stop there. The table is genuinely useful, so here it is, but the row that matters most is the last one.
| MSP | MSSP | |
|---|---|---|
| Main job | Keep IT running | Detect and respond to attacks |
| Measured on | Uptime, response times, tickets resolved | Time to detect, time to contain |
| Typical team | Service desk and engineers | Analysts in a security operations centre |
| Hours | Often business hours, sometimes 24/7 | 24/7, or it is not really a SOC |
| Security work | Preventive: patching, firewalls, MFA, backup | Detective: monitoring, triage, containment |
| Reports to | IT manager or operations | Risk, compliance or the board |
| UK regulatory status | Relevant managed service provider | Relevant managed service provider |
That last row is not a typo, and the next section explains it.
The more practical difference is what each is incentivised to do at two in the morning. An MSP measured on uptime wants the system back. An MSSP measured on containment may want that same system isolated and preserved so the intrusion can be understood properly. Those two instincts pull in opposite directions, and the handover between them is where most organisations actually get hurt.
Why UK Law Does Not Recognise the Difference
Here is the part the American comparison articles leave out, and it changes the MSP vs MSSP decision for any UK organisation.
The Cyber Security and Resilience Bill brings managed service providers into the NIS Regulations through a category called the relevant managed service provider. The government’s own factsheet on relevant managed service providers sets out the test, and it has nothing to do with whether a provider calls itself an MSP or an MSSP. A service qualifies if it is provided in the UK under a contract for the ongoing management of IT systems, and the provider connects to or obtains access to the systems the customer relies on. Whether that access is on site or remote makes no difference.
The factsheet’s own examples settle it. In scope: IT outsourcing such as remote support, helpdesks and infrastructure management. Also in scope, in the same list: managed security services, specifically a security operations centre and security information and event management. Out of scope: firms that install a system and walk away, software companies selling a product, and consultancies with no ongoing management.
So the two categories this article is comparing sit in one regulatory bucket. A pure security firm running your SOC is a relevant managed service provider. So is a general MSP running your service desk. Small and micro providers are excluded by size, although the Bill still allows them to be designated as critical suppliers.
The practical consequence is simple. When you ask a provider how it is preparing for the new duties, “we are a security company, not an MSP” is not an answer. We have written separately on what the Bill means if you are not regulated yourself.
Which One Does Your Organisation Need
Start from what you already have rather than from the category names.
You probably need an MSP first if nobody owns your IT day to day, if staff fix their own problems or ask whoever is good with computers, or if patching happens when somebody remembers. Monitoring for sophisticated attackers is not the pressing risk when nobody is applying updates. Get the operational base in place and a large share of the risk goes with it.
You probably need an MSSP if your IT already runs competently, in house or outsourced, but nobody is watching for intrusions outside working hours. The signals are familiar. A customer or regulator asks how quickly you would detect a compromise. A cyber insurance renewal asks about monitoring. Or you learn about an incident from somebody else. If that is where you are, our guide to what to compare before you buy an MSSP covers the shortlisting stage.
You probably need both if you hold regulated or sensitive data, if your contracts commit you to incident notification deadlines, or if a day of downtime would be material to the business. That describes most mid-market organisations, which is why the MSP vs MSSP framing turns out to be less of a choice than it first appears.
Why Most Organisations End Up Needing Both
Two things have collapsed the gap between the categories.
The first is that prevention and detection stopped being separable. An attacker using stolen credentials does not trip a firewall. They log in. Spotting that needs the identity telemetry an MSP holds and the analytic capability an MSSP brings, and when those sit in two different companies under two different contracts, the space between them is exactly where an intruder gets to live.
The second is commercial. Most MSPs now sell security services, and plenty of MSSPs have added IT operations, so the labels increasingly describe a company’s history rather than its scope. Reading the service catalogue tells you considerably more than reading the name above the door.
Which means the useful question is not MSP vs MSSP but who is accountable where the two overlap. If your IT provider and your security provider are different companies, settle in advance who makes the call to isolate a system, who speaks to your insurer, and who owns the clock on a reporting deadline. Those are expensive arguments to have for the first time during an incident.
What to Ask Before You Sign With Either
The government’s Cyber Security Breaches Survey 2025/2026 found that just 15% of businesses had reviewed the risks posed by their immediate suppliers, and 6% had looked at their wider supply chain. Your MSP or MSSP is a supplier holding privileged access to everything you own, which makes it a strange one to leave unexamined.
Six questions separate providers quickly, whichever letters they use.
- Who answers at 3am, and do they work for you? Round the clock cover can mean a staffed operations centre, an on-call rota, or an offshore first line. Those are very different products at similar prices.
- What exactly is monitored? Endpoints only, or identity, email, cloud and network as well? Most intrusions now begin with a login rather than malware.
- What happens when you find something? Ask whether they can contain and isolate, or only tell you. An alert with nobody authorised to act on it is not a response capability.
- How will you prepare us for the incoming UK duties? A provider that has not thought about the new regime has not thought about your reporting deadlines either.
- What is out of scope? The honest answer is never “nothing”.
- Can we speak to a client who has had an incident? Reference calls about the good times tell you very little.
Our longer guide on how to evaluate managed IT service providers works through the proposal and reference stages in more detail, and it applies equally on either side of the MSP vs MSSP line.
How Transputec Handles Both
Transputec runs both sides under one contract, which removes the handover problem described above rather than managing around it. The managed IT services side covers the service desk, infrastructure, networks and cloud platforms. The cyber security services side covers the security operations centre, managed detection and response, Microsoft Sentinel, vulnerability management, penetration testing and CISO level consultancy.
Both are run from London. The 24/7 service desk and the Security Operations Centre are both based in the city, which means the analyst who sees a suspicious login and the engineer who knows what that laptop is for are colleagues rather than two suppliers on a conference call. Delivery is ISO 27001 and Cyber Essentials Plus certified, and we are a listed supplier on the Government Commercial Agency G-Cloud 15 framework.
If you would rather see how the security side works before speaking to anybody, our explainer on how a managed SOC works covers what it monitors and what it costs.
The Short Version
An MSP runs your IT. An MSSP defends it. If nobody is doing the first job properly, start there, because monitoring an unpatched estate mostly generates alerts you cannot act on. If the first job is handled and nobody is watching out of hours, that is precisely what an MSSP is for.
Two things are worth carrying away from the MSP vs MSSP comparison. The categories have largely merged in practice, so read the service catalogue rather than the name. And UK law never recognised the distinction to begin with: under the incoming regime both are relevant managed service providers carrying the same duties. Ask any provider how it is preparing for that, and treat the answer as a test of the firm rather than a compliance formality.
If you want to have that conversation, Transputec delivers managed IT services and cyber security services from one London team under a single contract.
Frequently Asked Questions
Can one provider be both an MSP and an MSSP?
Yes, and most now claim to be. The question worth asking is whether the security side is a real capability or a reseller arrangement. Ask who staffs the security operations centre, whether it is genuinely covered around the clock, and whether they are authorised to contain an incident or only to report it. Transputec runs the service desk and the SOC from London under a single contract.
Is an MSSP more expensive than an MSP?
They are not directly comparable, because they are not the same product. Managed IT is normally priced per user or per device per month and covers broad operations. Managed security is more often priced on the number of endpoints or the volume of data monitored. A fair comparison needs the scope written down on both sides, not a headline rate, because the same monthly figure can buy very different things.
Does an MSSP replace my IT support?
No. An MSSP monitors and responds to security events. It will not run your service desk, manage your devices, handle procurement or migrate your email. Taking an MSSP with no IT provider in place leaves you with somebody to tell you about problems and nobody to fix them.
Is the MSP vs MSSP distinction disappearing?
In practice it has largely gone. Most MSPs now sell security services and many security firms have added IT operations, so the MSP vs MSSP label increasingly tells you what a company used to be rather than what it does today. The service catalogue and the contract are the reliable guide.
Does the Cyber Security and Resilience Bill treat MSPs and MSSPs differently?
No. The government’s factsheet on relevant managed service providers gives IT outsourcing and managed security services, specifically a security operations centre and security information and event management, as examples of the same in-scope category. If a provider delivers a managed service in the UK under contract and connects to your systems, the duties apply whichever label it uses.
This article was drafted with AI assistance and reviewed by the Transputec team. Featured image: AI-generated.
