The ten IT problems small businesses report most are slow computers, unreliable internet or WiFi, phishing and account takeover, backups that don't restore, relying on one person, unsupported software, messy Microsoft 365, phones tied to the office, leavers who keep access, and the same faults recurring. Each has a recognisable symptom and a usual cause. Most are fixed by monitoring, standard set-ups and a named owner, not by buying new kit.
Why do the same problems keep turning up?
Small businesses rarely have one big IT failure. They have a slow build-up of small ones: a laptop bought in a hurry, a password shared "just for now", a backup set up by someone who has since left. Each is harmless on its own. Together they cost hours every week and leave gaps attackers use.
Below, each problem is set out the same way: what you notice, what usually causes it, how to fix it, and how to stop it coming back. The quick table first, for anyone who wants the short version.
| Problem | First thing to check |
|---|---|
| 1. Slow computers | Age, disk space and whether updates are stuck |
| 2. Unreliable internet or WiFi | Speed test wired vs WiFi, and access point age |
| 3. Phishing and account takeover | Is MFA on for every account? |
| 4. Backups that don't restore | When was the last test restore? |
| 5. Relying on one person | Is anything written down? |
| 6. Unsupported software | Any Windows 10 or old server still running? |
| 7. Messy Microsoft 365 | Where are files actually saved? |
| 8. Phones tied to the office | Analogue lines or an old on-site system? |
| 9. Leavers who keep access | Any active accounts for people who've left? |
| 10. The same faults, again and again | Is anyone looking for root causes? |
The ten problems, one by one
1. Slow computers
Symptom: long start-ups, spinning wheels in Outlook, people keeping a second job to do while files open. Likely cause: usually age and neglect rather than a virus. Machines over four or five years old, near-full disks, too little memory for modern Microsoft 365 and browsers, or updates that have failed and keep retrying. Fix: check disk space and pending updates first, then memory. Often a clean-up and a faster solid-state drive (SSD) or more memory buys another year. If the machine can't run Windows 11, replace it. Prevent: a standard device specification, a replacement cycle (around four years for laptops), and monitoring that flags low disk space and failed updates before users notice.
2. Unreliable internet or WiFi
Symptom: Teams calls freeze, cloud files take ages, "the internet's down again" once a week. Likely cause: it's often the WiFi, not the line. Consumer routers, too few access points, or old kit struggling with more devices. Where the line itself is the problem, it's usually an old copper-based service or a line shared by too many users at busy times (contention). Fix: test speed on a cable next to the router and again over WiFi. If the cable is fine, fix the WiFi with business-grade access points placed properly. If the line is slow, check what's available: SoGEA broadband (broadband without a phone line) costs about £32 a month and full fibre (FTTP) £32–£50 depending on speed. Ofcom reports full fibre is now available to 71% of Scottish homes, but coverage drops sharply outside towns. Prevent: add a 4G/5G backup connection, so one fault doesn't stop the business.
3. Phishing and account takeover
Symptom: a customer asks why you emailed them a strange invoice; a staff member "entered their password on a Microsoft page"; mailbox rules appear that forward mail elsewhere. Likely cause: a convincing phishing email and an account without multi-factor authentication (MFA, a second check when people sign in). Phishing affected 38% of UK businesses in the last year, according to the government's 2026 survey, while only 47% of businesses use MFA. Fix: reset the password, sign the user out everywhere, remove any forwarding rules, check what was sent and tell affected contacts. Report it to Action Fraud if money was involved. Prevent: MFA on every account, advanced email filtering, short regular phishing training, and a rule that bank detail changes are confirmed by phone on a known number.
4. Backups that don't restore
Symptom: you only find this one when you need it. Someone deletes a folder, you go to the backup, and it stopped months ago or holds the wrong data. Likely cause: backups set up once and never checked, or the belief that Microsoft 365 backs itself up. Microsoft keeps the service running; restoring deleted or encrypted data beyond its short retention windows is your responsibility. Fix: confirm what's backed up (servers, laptops, Microsoft 365 mail, OneDrive, SharePoint and Teams), where copies live and how long they're kept. Prevent: automated backups with daily success reports, one copy kept separately from your main systems, and a test restore at least twice a year.
5. Relying on one person
Symptom: everything waits for "Dave". When Dave's on holiday, nobody can add a user or knows the WiFi password. Likely cause: IT grew around one helpful person, and nothing got written down. Fix: document the essentials: admin accounts, suppliers, licences, network details, renewal dates. Store them securely, not in a spreadsheet on Dave's desktop. Prevent: keep documentation current as part of normal work, and make sure at least two people, or a support provider, can access every admin account.
6. Unsupported software
Symptom: a program that "only works on that one PC", a server in a cupboard nobody wants to touch, warnings that Windows is out of support. Likely cause: delayed upgrades. Windows 10 reached end of support on 14 October 2025, and paid extended updates for businesses are bought a year at a time and cost more each year. Fix: list everything out of support and give each item a date: upgrade, replace or retire. Prevent: track software lifecycles in your IT plan so upgrades are budgeted, not emergencies. Unsupported systems also fail Cyber Essentials.
7. Messy Microsoft 365
Symptom: files on desktops, three versions of the same document, links shared with "anyone", people paying for licences they don't use. Likely cause: Microsoft 365 was switched on for email and never set up properly beyond that. Fix: move shared files into SharePoint and Teams with sensible permissions, turn on OneDrive known-folder backup, tighten external sharing, and review licences. Our article on saving money on Microsoft 365 licences covers the last part. Prevent: a yearly Microsoft 365 review covering security settings, sharing and licences.
8. Phones tied to the office
Symptom: calls go to voicemail when people work from home or on site; nobody can see missed calls; adding a line takes weeks. Likely cause: an on-site phone system or analogue lines. Openreach closes the analogue network on 31 January 2027, so these need to move anyway. Fix: move to a cloud phone system that rings on desk phones, laptops and mobiles, with call reporting. Prevent: check alarms, lift lines, card machines and door entry at the same time, because they often use the same old lines.
9. Leavers who keep access
Symptom: an audit finds active accounts for people who left last year, or a former employee still has shared files on their phone. Likely cause: no leavers process, and shared passwords that never change. Fix: disable leavers' accounts, convert mailboxes you need to keep into shared mailboxes, remove their devices from company data, and change any shared passwords they knew. Prevent: a one-page leavers checklist triggered by HR or payroll on the last day, and managed devices so data can be removed remotely.
10. The same faults, again and again
Symptom: the same printer, the same VPN, the same person's laptop, every week. Likely cause: support that fixes the symptom and closes the ticket, with no one looking at patterns. Fix: ask for a report of your tickets by category over three months and pick the top three recurring issues for a permanent fix. Prevent: proactive support with monitoring and regular reviews, where a good provider brings you the patterns before you ask.
What we see on our service desk
Indigo's helpdesk sees all ten of these every month. In September 2026 we handled 1,854 tickets, with an average first response of 13 minutes and 65% resolved within 2 hours. The quick fixes matter, but the bigger win is spotting that the same three causes (unmanaged devices, missing MFA and no documentation) sit behind most of the repeat tickets, and fixing those once.
How Indigo does this. Indigo Unified Communications supports businesses of 10 to 500 staff from Glasgow and Livingston with an experienced engineering team across three support lines. We prevent these problems by monitoring your devices and keeping them updated (Datto RMM), protecting them against viruses and ransomware (Kaseya 365 Endpoint), filtering email with INKY, managing devices with Microsoft Intune, backing up Microsoft 365 with Datto SaaS Protection and documenting everything in IT Glue. Managed IT support →
What to do next
- Go through the quick table and mark each problem "yes", "sometimes" or "no" for your business.
- Fix anything touching security first: MFA, leavers' accounts and backups.
- Check your line options and a 4G/5G backup on our connectivity availability checker.
- Score your wider set-up with the 30-minute IT audit.
- If you're fixing the same things every month, see what switching to Indigo involves.
Frequently asked questions
What is the most common IT problem in small businesses?
Slow or unreliable devices are the most visible, but the most damaging is weak account security. Phishing affected 38% of UK businesses in the government's 2026 survey, and fewer than half of businesses use multi-factor authentication. A stolen password on an account without MFA can lead to invoice fraud, data loss and days of disruption, which costs far more than a slow laptop.
Should I fix IT problems myself or call a professional?
Simple checks are fine to do yourself: restarting, checking disk space, running a wired speed test or confirming MFA is on. Call a professional for anything involving a possible security breach, data recovery, network changes or admin settings in Microsoft 365, because mistakes there can lock people out or hide evidence. If you're fixing the same issue repeatedly, that's also a sign you need help.
How often should business computers be replaced?
Most businesses replace laptops about every four years and desktops every four to five. Replace sooner if a device can't run a supported operating system such as Windows 11, fails regularly or slows people down daily. Planning replacements on a rolling cycle spreads the cost and avoids a large bill when several machines fail at once.
Is slow internet usually the line or the WiFi?
Often the WiFi. Test speed on a device plugged into the router with a cable, then again over WiFi in the same spot. If the cabled result is good, the problem is the wireless network, often consumer kit or too few access points. If the cabled result is poor, look at the line itself and what better options are available at your address.
Sources: DSIT, Cyber Security Breaches Survey 2025/2026, 30 April 2026 (https://www.gov.uk/government/statistics/cyber-security-breaches-survey-20252026/cyber-security-breaches-survey-20252026) · Ofcom, Connected Nations: Nations report 2025, 19 November 2025 (https://www.ofcom.org.uk/phones-and-broadband/coverage-and-speeds/nations-report-2025) · Microsoft Learn, Extended Security Updates (ESU) program for Windows 10 (https://learn.microsoft.com/windows/whats-new/extended-security-updates) · Openreach, Time for a big switch-up as PSTN switch-off looms, 5 February 2026.
Related: How to audit your IT in 30 minutes · Phishing: what it is and how to stop it · The UK PSTN switch-off explained · Managed IT support
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