Since Brexit, HMRC has significantly increased its scrutiny of customs declarations. The UK’s departure from the EU has introduced new complexities in cross-border trade, and HMRC is now more active than ever in investigating potential non-compliance. Businesses and individuals involved in international trade are seeing a rise in enquiries, inspections, and - where dishonesty is suspected - civil investigations under Notice 300.

These investigations can involve reviewing business records, inspecting goods, and in more serious cases, detaining or seizing items. Understanding your rights and obligations is essential, particularly when HMRC alleges dishonest conduct.

What is Notice 300?

Notice 300 sets out HMRC’s procedures for civil investigations into suspected evasion of customs duties. It applies where HMRC believes there may have been dishonest behaviour, such as:

• Smuggling by travellers or traders

• Fraudulent customs declarations

• Dishonest claims for relief or repayment of duty

These investigations are serious and can have significant financial and reputational consequences. However, taxpayers have rights—and knowing how to respond can make all the difference.

Are you required to attend a meeting with HMRC?

When HMRC opens a Notice 300 investigation, it often invites the taxpayer to attend a meeting. While this may be presented as routine, you are not legally obliged to attend. HMRC’s own guidance confirms that meetings are optional, and taxpayers may choose to respond in writing or through a professional adviser.

This approach can be particularly effective, allowing for careful review of all communications and ensuring that responses are clear, accurate, and fully documented.

If however you’re the subject of a code of practice 9 investigation and have accepted HMRC's CDF offer, then you must personally meet with HMRC when requested. Otherwise, your presence is not mandatory. 

Case study: strategic representation makes a difference 

In a recent case, HMRC opened a Notice 300 investigation into a client’s customs declarations and invited the company’s directors to attend a meeting with its specialist team.  

Meetings with HMRC can become confrontational and extremely stressful. Concerned about the implications of attending a meeting, the directors appointed us to represent them. Following our review, we considered that a meeting with HMRC was not necessary and not in the directors’ best interests. The client respectfully declined the meeting, reiterating their willingness to cooperate fully in writing. Despite having submitted detailed written representations, HMRC continued to insist that a face-to-face meeting would be the most efficient and beneficial way to resolve the matter. HMRC’s invitation was again declined by our client. 

It was clear to us from the outset that no fraud had occurred. Confident in our client’s position, we invited HMRC to issue its decision and made it clear that, should HMRC wish to proceed with issuing a civil evasion penalty, we would expect a full explanation of the basis for their suspicions and disclosure of the evidence supporting their view that fraud was involved. 

Shortly thereafter, HMRC informed us that, upon further review, an investigation under Notice 300 was no longer appropriate and they would not be proceeding with the case. 

This outcome underscores the importance of knowing your rights and engaging experienced representation. It also raises important questions: 

• Was HMRC’s initial suspicion substantiated, or was the meeting intended to gather further evidence? 

• Would the meeting have served to clarify the facts, or simply to strengthen HMRC’s position? 

Key takeaways for businesses and advisers

• Know your rights: Receiving a Notice 300 letter is serious, but it does not remove your right to choose how you engage with HMRC. Meetings are optional, and written communication is a valid and often preferable alternative.

• Seek specialist advice: Customs investigations require technical expertise. Engaging a tax specialist with experience in HMRC procedures ensures your case is handled professionally and proportionately.

• Document everything: Keep detailed records of all correspondence with HMRC. This protects your position and ensures transparency.

• Don’t be pressured: An invitation to a meeting is just that—an invitation. HMRC may imply that declining a meeting ref