Tax Return Penalties: Deadlines, Fines, and Conditions for Reductions

Penalties for Filing Welsh Tax Returns Late

If a required Welsh tax return for Land Transaction Tax (LTT) or Landfill Disposals Tax (LDT) is filed late, the Welsh Revenue Authority can charge penalties. The first penalty is usually £100 as soon as the deadline is missed, with extra penalties at 6 and 12 months if the return is still outstanding. More serious penalties can apply where information has been withheld, and penalty notices are normally payable within 30 days unless a review or appeal is made.

• A late LTT or LDT return usually triggers an immediate fixed penalty of £100.
• If the return is still not filed after 6 months, there is a further penalty of £300 or 5% of any unpaid tax, whichever is higher.
• If the failure continues to 12 months, another penalty of £300 or 5% of unpaid tax, whichever is higher, can be charged.
• For LTT, the filing deadline is 30 days from the transaction’s effective date, usually completion; for LDT, it is the last working day of the month after the accounting period ends.
• If the taxpayer withholds information that would help the WRA assess the tax, the penalty can be much higher, potentially up to 95% of the tax due, although reductions may be possible if the information is later disclosed.
• Penalties must normally be paid within 30 days of the penalty notice unless the taxpayer asks for a review or appeals to the tribunal.

Scroll down for the full analysis.

Penalties for missing a Welsh tax return filing deadline

This page explains the penalties that can arise if a required Welsh tax return is not filed on time. The source material covers Land Transaction Tax (LTT) and Landfill Disposals Tax (LDT). The main point is simple: if a return is due and it is not filed by the deadline, a fixed penalty starts straight away, and further penalties can follow if the failure continues. In more serious cases, the penalty can be much higher if information is deliberately withheld.

What this rule is about

The Welsh Revenue Authority (WRA) can charge penalties where a taxpayer is required to file a tax return but does not do so by the filing date. This is a filing obligation penalty. It is separate from the tax itself.

The rule matters because filing late can trigger penalties even before considering any interest or consequences for unpaid tax. It also matters because the amount can increase over time, and the rules are stricter where the taxpayer has withheld information that would help the WRA assess the tax properly.

What the official source says

The source says that a taxpayer who is required to make a tax return is liable to a £100 penalty if the return is not made on or before the filing date.

For LTT, the filing date is 30 days from the effective date of the transaction. The source notes that this is usually the completion date.

For LDT, the filing date is the last working day of the month following the month in which the accounting period ends.

If the failure continues, further penalties apply:

• 1 day late: £100
• 6 months late: an extra £300 or 5% of any unpaid tax, whichever is greater
• 12 months late: another £300 or 5% of any unpaid tax, whichever is greater

The source then sets out a more serious rule. If the taxpayer withholds information that would enable or assist the WRA to assess their liability to a devolved tax, the penalty amount is the greater of:

• £300, or
• an amount not exceeding 95% of the devolved tax that would have been due if the return had been made

The source also says that these penalties must be paid within 30 days beginning with the date on which the penalty notice is issued, unless the taxpayer asks for a review or appeals to the tribunal.

Finally, the WRA may reduce a penalty for failure to make a return if the taxpayer discloses information that had been withheld because of that failure.

What this means in practice

The practical effect is that missing a filing deadline can become expensive quite quickly.

If a return is due and is filed late, the initial penalty is £100. If the return is still outstanding at the 6-month point, there is a further penalty. If it is still outstanding at 12 months, there is another further penalty.

The 6-month and 12-month penalties are not always fixed at £300. They are whichever is greater: £300 or 5% of any unpaid tax. So where a significant amount of tax remains unpaid, the penalty can be higher than £300.

The rule about withholding information is more serious. It applies where the taxpayer has not simply been late, but has withheld information that would enable or assist the WRA to assess the tax liability. In that situation, the penalty can rise well beyond the standard late-filing amounts, potentially up to 95% of the tax that would have been due if the return had been filed.

The source does not say that the maximum 95% will always apply. It says the penalty is the greater of £300 or an amount not exceeding 95% of the tax. That means there is scope for the actual amount to depend on the circumstances.

How to analyse it

If you are trying to work out whether a penalty may arise, the sensible questions are:

• Was there a legal obligation to file a return?
• What was the filing date?
• Was the return filed on or before that date?
• If not, how long did the failure continue?
• Was any tax unpaid at the 6-month or 12-month point?
• Has the taxpayer withheld information that would help the WRA assess the tax?
• Has the taxpayer since disclosed withheld information, so that a reduction might be available?
• Has a penalty notice been issued, and if so, when does the 30-day payment period end?
• Has the taxpayer requested a review or appealed to the tribunal?

For LTT, it is especially important to identify the effective date of the transaction correctly, because that is what starts the 30-day filing period. The source says this is usually completion, which implies that it may not always be completion. In some cases, working out the effective date is itself an important first step.

For LDT, the filing date depends on the end of the accounting period and then the last working day of the following month. That means the calendar calculation matters.

Example

Illustration: a person is required to file an LTT return. The effective date of the transaction is 1 June, so the filing deadline is 30 days later. If no return is filed by that deadline, the £100 late-filing penalty arises. If the return is still not filed 6 months later, there is a further penalty of £300 or 5% of any unpaid tax, whichever is greater. If the failure continues to 12 months, another penalty of the same type arises.

If, in addition, the person has withheld information that would help the WRA work out the tax due, the penalty position may be more serious than the standard late-filing amounts. The source indicates that the penalty can then be set by reference to the tax that would have been due, up to a maximum of 95%.

Why this can be difficult in practice

The source is clear on the basic penalty structure, but some points are fact-sensitive.

First, the penalty only applies if a return was required. In some cases, that may itself need analysis.

Second, the filing date must be identified correctly. For LTT, the source says the effective date is usually completion, but not always. If the effective date is wrong, the penalty analysis may also be wrong.

Third, the more serious penalty for withholding information depends on what was withheld and whether it would have enabled or assisted the WRA to assess the liability. That can involve questions of fact and degree.

Fourth, the source says the WRA may reduce a penalty if withheld information is later disclosed. It does not set out in this extract how any reduction is calculated. So the possibility of reduction is clear, but the amount of any reduction will depend on the wider rules and the facts.

Finally, the source says penalties must be paid within 30 days of the notice unless the taxpayer requests a review or appeals to the tribunal. That means timing matters not only for filing the return, but also for responding to the penalty notice itself.

Key takeaways

• A required LTT or LDT return filed after the deadline triggers an initial £100 penalty.
• If the failure continues for 6 months and 12 months, further penalties arise, based on £300 or 5% of unpaid tax, whichever is greater.
• Where information has been withheld that would help the WRA assess the tax, the penalty can be much higher, though the source indicates the WRA may reduce it if the information is later disclosed.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Tax Return Penalties: Deadlines, Fines, and Conditions for Reductions

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