Managed IT Support
How many computers before you need IT support? The five-device threshold and an employee-count guide
How many computers or employees justify IT support for a small business: why five devices is the usual tipping point, what changes at 10, 20 and 30 staff.
By Dig IT SolutionsUpdated 8 September 20265 min read
Short answer
Around five computers is the point at which most small businesses need structured IT support, because shared files, a network, Microsoft 365 accounts and security updates start needing consistent oversight. Below five, a cloud-only team can manage with MFA, a tested backup and a provider on call. Sensitive data, a server or remote working bring the threshold down to one.
Business owners ask this because they want a number, and the honest answer is that there is one: around five computers. Below that, an informal arrangement can work if the basics are in place. Above it, the time and risk of managing things yourself outgrow the cost of a contract. This guide explains why five, what changes at each headcount stage, and the three factors that bring the threshold down to one.
Why five computers is the tipping point
With one or two computers, IT is personal. You know what is on each machine, you update it when prompted, you keep your files somewhere sensible.
At five, IT becomes shared. Staff use the same files, the same applications and the same network. A permissions mistake on the shared drive affects everyone. An unpatched laptop is a route into the others. New starters need accounts, leavers need removing, and someone has to do it every time, consistently.
Five is also where the informal IT person's time becomes visible. Five machines to update, five sets of problems to solve, five people asking. The owner or office manager who was "good with computers" is now spending hours a week on it, and those hours have a cost that does not appear on any invoice.
Nothing dramatic happens at five. It is simply the point at which a contract for five devices, at our indicative rate of £17.50 per computer per month, costs less than the time and risk of doing without.
Three factors that override the count
The device count is a proxy for complexity. Three things push the real threshold much lower.
Sensitive data. If you hold client files, patient records, payroll, financial details or anything you could not recreate, you need managed security and tested backup from the first computer. A sole-practitioner accountant with one laptop and a ransomware infection has the same problem as a firm of fifty. The ICO does not scale its expectations by headcount.
A server, NAS or shared network. The moment there is shared infrastructure, somebody has to patch it, back it up, and control who can reach it. A server is a single point of failure that our indicative rates price at £150 a month to support, for good reason.
Remote working. Staff on home networks and personal devices need managed endpoint protection, MFA and secure access. Two remote workers create more exposure than five people in one office.
Any one of these and the answer is "now", regardless of how many computers you have.
What changes at each stage
| Staff and devices | What is happening | What IT support needs to cover | Indicative monthly cost on per-device rates |
|---|---|---|---|
| 1 to 4 | Laptops and cloud apps, no server, possibly no office | MFA, automatic updates, Microsoft 365 backup, a provider on call | Often ad hoc, or £17.50 per computer plus £25 for a firewall if there is an office |
| 5 to 9 | Shared files, a network, Microsoft 365 accounts, first hires | Monitoring, patching, managed endpoint security, backup checks, helpdesk, joiners and leavers | Five laptops and a firewall: about £112 |
| 10 to 19 | Departments forming, a printer or two, remote workers, possibly a server | Everything above plus permissions management, remote access controls, licence reconciliation, hardware planning | Ten laptops, a firewall, a printer: about £210, plus £150 if there is a server |
| 20 to 30 | Multiple teams, more devices than staff, higher attacker interest, possibly a second site | Network segmentation, documented recovery procedures, regular reviews, awareness training, site-to-site connectivity | Twenty-five laptops, a server, a firewall, two printers: about £632 |
| 30 to 50 | Whole departments depend on systems, downtime is expensive, compliance questions arrive | Structured onboarding and offboarding, reporting, strategy reviews, Cyber Essentials | Scales per device, use the calculator |
| 50+ | Complex enough to justify an internal IT lead | Co-managed IT: internal lead plus external monitoring, security, escalation and cover | Scales per device, plus the internal salary |
Figures use our indicative per-device rates (reviewed October 2026, confirmed in a written quote) and exclude phones, licences, hardware and projects. The IT support cost calculator will run them for your own equipment, and how much IT support costs in the UK explains the ranges.
The cost of getting it wrong at small scale
Small businesses are where IT failures do the most proportional damage, because there is no buffer.
A five-person practice that keeps client files on one PC with no tested backup loses weeks when the disk fails, and possibly the files. A three-person business whose Microsoft 365 accounts have no MFA loses its mailbox to a phishing attack and spends a fortnight explaining fake invoices to customers. A ten-person firm whose only IT person leaves discovers nobody knows the firewall password or where the backups go.
Each of these costs more than a year of support for the devices involved. The pattern is described in why unresolved IT issues become expensive.
Signs you are already past the threshold
Whatever the count, these mean the informal approach has stopped working.
- You have needed outside help more than once in the last six months.
- The same problems recur: Wi-Fi, printers, Outlook passwords.
- New starters wait days for a laptop and access.
- Nobody has tested a backup restore.
- Someone has clicked a phishing link, or nearly.
- The owner or office manager spends hours a week on IT.
- An insurer, client or accountant has asked what security you have.
- You are about to hire, open a second site or move office.
Two or more and the question is not whether, but what kind. Does my business need IT support? works through the decision, and break-fix versus managed IT support compares the two ways of buying it.
What the smallest sensible contract looks like
For a five-person business, a managed contract does not need to be elaborate. It should cover monitoring and patching of each computer, managed endpoint security, MFA enforced on Microsoft 365, a backup that is checked and restore-tested, a helpdesk staff can contact directly, and joiners and leavers handled properly. That is the managed IT support core, priced per device, and it is the same service a 50-person firm gets, at a fifth of the cost.
What to do next
If you are around five computers, or below it with sensitive data or a server, the IT support cost calculator will give you an indicative monthly figure for your actual equipment in a couple of minutes. Put it next to what the last IT problem cost you in time, and the decision is usually straightforward.