HMRC Penalties & Investigations

HMRC Penalties & Investigations: What You Must Know in 2025

Whether you are a limited company, landlord, or self-employed person, receiving a call from HMRC regarding a tax investigation can be a worrying experience. In 2025, with new digital systems and stricter penalties in place, HMRC has become quicker and more precise in identifying mistakes and non-compliance.

At Taxaccolega Accountants, we’ve compiled a brief, up-to-date guide to the penalties HMRC can issue and how you can avoid HMRC penalties in the UK.

Why Might HMRC Investigate You?

• Discrepancies in your self-assessment or VAT returns

• Unexplained falls in reported income

• Third-party anonymous tips or red flags

• Unreported earnings from digital platforms (eBay, Etsy, Vinted)

• Incomplete or missing records

What Penalties Can HMRC Charge You?

1. Errors on Your Tax Return

• Careless mistake: 0–30% of tax due

• Deliberate mistake (not hidden): 20–70%

• Deliberate and hidden: 30–100%

What to do	What to avoid
Tell HMRC before they discover it (lower penalties for voluntary disclosure)	Guessing figures or omitting side income
Work with a tax adviser to get your return right the first time	Ignoring HMRC letters or emails

2. Failure to Notify HMRC About Changes

Examples:

• Your business hits the VAT threshold

• You sell a second property and owe Capital Gains Tax

• You move income offshore

• Penalties are 10% to 100% depending on whether it was an innocent mistake or intentional.

What to do	What to avoid
Inform HMRC promptly of significant business or financial change	Notifications late – the longer, the more penalties impose
Maintain complete records of sale proceeds, property income, crypto trading, etc.

3. Penalties for Late Filing (Self-Assessment, VAT, Corporation Tax)

Why Self-Assessment, VAT, Corporation Tax penalties happen (UK)?

It happens when a business or individual fail to meet tax obligations like filing tax return late, paying amount late or submit incorrect information.

HMRC Self-Assessment Penalties (2025)

• 1 day late: £100

• 3 months late: £10/day (up to £900)

• 6 months: 5% of unpaid tax or £300

• 12 months: additional 5% or £300

HMRC penalty for VAT return (under new digital rules)

• 1 point for each missed deadline

• £200 fine when you reach your penalty threshold (e.g. 4 points for quarterly VAT)

• Points expire after 24 months if you comply

What to do	What to avoid
File all returns on time using digital software	Leaving it to the last minute
Use digital tax software	Supposing HMRC won’t notice missing returns
To avoid tax return penalties in UK Set calendar reminders for key dates: 31 Jan(filing/payment), 31 July (payment on account)	Ignoring penalty notices
Keep good records throughout the year	Not updating HMRC with changes

4. Late Payment Penalties (NEW for 2025)

• After 15 days: HMRC may charge 3% late penalty if no Time to Pay arrangement

• After 30 days: 3% penalty

• Plus, daily interest: Base rate + 4% (currently ~8.25%)

Things to do	Things not to do
Pay your tax early or set up a Time to Pay (TTP) plan with HMRC	Disregarding payment reminders
Keep your business savings account separate to manage tax funds	Waiting for penalty notices to be sent

5. Serious Tax Avoidance

If HMRC suspects fraud or deliberate evasion, you could face:

• Criminal investigation

• Asset seizure

• Unlimited fines

• A maximum sentence of seven years in prison

What to do	What to Avoid
Be transparent honesty significantly reduces penalties	Hide income (offshore, crypto, undeclared cash)
Hire a tax investigation expert (like us!) if contacted by HMRC	Disregard tax submission requirements

How to Protect Yourself from Penalties in 2025

What You Need to Do:

• Practise cloud accounting software like Xero or QuickBooks

• Maintain digital copies of receipts and bank statements

• Consult an accountant one a quarter to review your tax position

• Voluntarily disclose any past tax mistakes

• Keep yourself updated on Making Tax Digital (MTD) deadlines

• Register for HMRC services (e.g., VAT, Self Assessment) as soon as you become eligible

What You SHOULD NOT Do:

• File tax returns late

• Estimate income without supporting documents

• Rely on outdated tax rules

• Assume “side hustle” income is exempt from tax

• Use offshore accounts or undeclared crypto wallets to avoid tax

Help with HMRC fines and penalties

Check the HMRC letter that will show what is the type of penalty, how to appeal, check your account with HMRC to make sure there has not been a mistake, pay the fine if valid, otherwise use HMRC penalty appeal services write a letter to HMRC and explain the whole situation.

Note: HMRC interest charges cannot usually be appealed — they are automatic.

There must be reasonable excuse to cancel or reduce the penalty

• Like serious illness

• Fire flood or theft

• Family grief

• HMRC online service failure

Real 2025 Changes You Need to Know

• Late payment penalties now apply after just 15 days

• Interest rates for late tax have risen to over 25%

• Making Tax Digital rollout continues — MTD for ITSA applies to those earning over £50k from April 2026. Lower thresholds will follow by 2028.

• HMRC now tracks online seller income (eBay, Vinted, Amazon, Airbnb) more closely

Do You Need Help? Allow Taxaccolega to Assist

Based in Croydon, London, we are a group of skilled, tech-savvy accountants that assist people and companies all over the UK in maintaining efficiency, compliance, and stress-free operations.

Our Services:

• Self-Assessment & Corporation Tax returns

• Defence and representation in HMRC enquiries

• VAT registration & filings

• Digital recordkeeping solutions (Xero, MTD setups)

• Guidance on cryptocurrency assets and offshore income

Final Word

HMRC is getting stricter and smarter every year. Getting the right advice early, staying organised, and being honest are the best ways to protect yourself in 2025. Choose a trustworthy accountant who prioritises your financial well-being to avoid needless worry and expensive fines.