How to Protect Your Business from Phishing Emails

If your inbox is filling up with suspicious emails, you are not imagining it. Phishing is now the most common cyber attack hitting UK businesses, with 85% of businesses that reported a breach in 2025 saying phishing was involved. That is not a niche problem. That is something almost every business owner running a team of any size is dealing with right now.

The good news is that you do not need to become a cyber security expert to get this under control. You just need the right setup and your staff to know a few basic things to watch out for.

What Phishing Actually Is

A phishing email is one designed to trick someone into doing something they should not do. That might be clicking a link that installs something nasty on your machine. It might be entering your login details on a fake website that looks like Microsoft or your bank. Or it might be approving a payment to an account that belongs to a criminal, not your supplier.

The emails used to be easy to spot. Bad spelling, odd formatting, a Nigerian prince asking for your help. That is not what they look like now. The ones landing in UK business inboxes today are well written, correctly branded, and often reference real details about your business or your suppliers. Some of them are frighteningly convincing.

The Invoice Fraud Problem

One of the most damaging types hitting UK businesses right now is invoice fraud. Here is how it typically plays out. You receive an email that appears to come from a supplier you use regularly. The email says their bank details have changed and asks you to update your records before the next payment goes out. The email looks legitimate. The tone is normal. You update the details. The next payment goes straight to a criminal's account.

By the time anyone realises what has happened, the money is gone. Banks can sometimes recover funds if you act fast, but there is no guarantee. The rule that can save you a significant amount of money is simple: never change supplier payment details based on an email alone. Always call the supplier directly, using a number you already have saved, not one listed in the email.

Why Microsoft 365 Does Not Catch Everything

A lot of business owners assume that because they are using Microsoft 365, their email is protected. It offers some filtering, but it has gaps that attackers are actively exploiting.

Microsoft themselves warned in early 2026 that attackers are abusing misconfigurations in email routing to make phishing emails appear as though they came from inside your own organisation. If your domain authentication settings (the technical records that tell the internet who is allowed to send emails on your behalf) are not set up correctly, a criminal can send an email that looks like it came from your own company. It passes straight through the filter and lands in your colleague's inbox looking entirely legitimate.

These configuration issues are not something most business owners would ever know to check. They sit quietly in the background until someone clicks the wrong thing. Getting them properly set up is one of the most effective things you can do to reduce your exposure, and it is the kind of thing a good IT support partner should be handling for you as standard.

The Attacks Are Getting Harder to Spot

Phishing is no longer something only careless people fall for. The attacks targeting UK businesses in 2026 are more targeted, more personalised, and harder to detect than they were even two years ago. Criminals research their targets. They look at your website, your LinkedIn, your Companies House filing. They know who your directors are, who your accountant is, and sometimes which software your business uses.

A staff member receiving an email that appears to come from the managing director asking them to urgently process a payment is not being stupid if they act on it. They are being human. That is exactly what the attack is designed to exploit.

What Actually Works

There is no single thing that stops phishing entirely. What works is a combination of the right technical setup and staff who know what to look for. Neither one alone is enough.

On the technical side, the basics that make a real difference are: proper email authentication on your domain, multi-factor authentication on all accounts (especially email and finance tools), and a good spam filter that goes beyond what Microsoft 365 includes by default. If someone does steal a password, multi-factor authentication means they still cannot get in without a second form of verification. It is one of the simplest and most effective controls available.

On the human side, staff do not need a full cyber security course. They need to know three things. First, if an email asks you to click a link and enter your login details, go directly to the website instead of using the link. Second, if a supplier or colleague asks you to make or change a payment by email, verify it by phone before doing anything. Third, if something feels slightly off about an email, trust that instinct and check before clicking.

What Poor Email Security Actually Costs

Beyond the immediate risk of losing money to invoice fraud, there are other costs that business owners do not always factor in. If a staff member's email account gets compromised, attackers can sit inside that account for weeks reading emails, learning your business, and then targeting your clients and suppliers with convincing fraud attempts using your real email address. The reputational damage from that can be significant and hard to recover from.

There is also the time cost. Dealing with a phishing incident, resetting accounts, notifying affected parties, checking whether anything was accessed or stolen, takes hours or days of management time that your business simply cannot afford to lose.

The UK government's 2025 cyber security survey found that 43% of UK businesses experienced a breach or attack in the previous 12 months. For medium-sized businesses with 30 to 50 staff, the risk is real and the consequences of getting it wrong go well beyond a few embarrassing emails.

Getting the Right Setup in Place

The businesses that handle this well are not necessarily spending large amounts of money on complex security systems. They have the basics done properly. Their email is configured correctly. Their staff know what to look out for. And they have someone they can call quickly if something suspicious comes through.

If you are not confident that your email setup is as secure as it should be, or if you are not sure whether your Microsoft 365 configuration has the gaps described above, it is worth getting it checked. Most of the time the fixes are straightforward. It is the not knowing that leaves businesses exposed.

Talk to Tech Optimised about securing your email. We will take a look at your current setup, tell you honestly what needs attention, and get it sorted without overcomplicating it.