Making Tax Digital: an introduction

Making Tax Digital (MTD) is HMRC’s initiative to digitise the UK’s tax system, making it easier for taxpayers to manage their obligations while reducing administrative errors. It requires businesses and individuals to keep digital records and submit updates using compatible software, rather than relying on paper-based methods.

MTD is therefore part of the UK government’s effort to create a more modern, digital-first tax system. It shifts the work of tax reporting from manual processes to digital tools, where records are stored electronically and submissions are made via software that connects directly to HMRC’s systems.

The core idea is to automate much of the tax process, helping to close the “tax gap” caused by errors or underreporting. It’s not a new tax but a change in how existing taxes are handled.

While it promises efficiency gains, some evidence suggests mixed results in practice, with benefits like fewer errors not always realised for all users. MTD has been rolled out in phases, starting with VAT, and plans for Income Tax are underway, but Corporation Tax extensions were canceled in 2025.

Find out more from https://sovos.com/vat/tax-rules/uk-making-tax-digital/

How HMRC processes paper returns: the hidden wiring

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HMRC Paper Tax Return Processing: A Stage-by-Stage Guide

Think of HMRC’s paper tax return processing like a factory assembly line where each document passes through multiple quality control checkpoints. Each stage has specific legal requirements, timings, and potential bottlenecks. Here’s how it works:


STAGE 1: Receipt and Logging

What Happens

Returns arrive at HMRC and are first logged into the Local Data Capture (LDC) system – a separate computer system specifically for processing returns.

Legal Basis

  • Section 8 & 8A TMA 1970: Returns must provide “information reasonably required for the purpose of establishing the amounts in which a person is chargeable”

Key Infrastructure Limitation

LDC operates independently – it cannot access the main computer system during logging and capture. This is like having a sorting facility that can’t see the main warehouse inventory while sorting packages.

Delays Can Occur From:

  • High volume periods (October deadline creates bottlenecks)
  • Returns arriving without proper identification
  • Physical damage to documents requiring special handling

STAGE 2: Initial Assessment & Triage

What Happens

Returns are assessed for quality and completeness. They’re categorized as either:

“Process Now” – Straightforward returns that can be processed quickly

  • or – Requiring Repairs – Returns needing corrections before full processing

Legal Authority for Repairs

Section 9A TMA 1970 permits HMRC to repair “obvious errors and mistakes” within 9 months of receiving the return

Types of Issues Identified:

  1. Obvious errors (arithmetic mistakes, wrong figures carried forward)
  2. Unsatisfactory returns – failing to meet Section 8 TMA 1970 requirements

Delays Can Occur From:

  • Unsatisfactory returns requiring correspondence with taxpayers before processing
  • Complex cases needing manual review
  • Returns with more than 10 repairs (requiring separate letters instead of automated processing)

STAGE 3: Data Capture & Entry

What Happens

Return information is entered into the LDC system through the CAPTURE RETURN function. This is manual data entry by HMRC staff.

Infrastructure Limitations

This is a significant bottleneck – think of it as transcribing handwritten documents into a computer, one box at a time. Unlike online returns that arrive digitally, paper returns require:

  • Manual reading of handwriting
  • Interpretation of figures
  • Entry into multiple data fields

Delays Can Occur From:

  • Illegible handwriting requiring clarification
  • Volume surges after October 31st deadline
  • Staff availability – limited number of operators with necessary user roles
  • Complex returns with multiple supplementary pages taking longer to process
  • Partnership returns requiring additional Standard Accounts Information (SAI) capture

STAGE 4: Revenue Calculation (If Requested)

What Happens

If the taxpayer requested HMRC to calculate their tax (rather than doing it themselves), HMRC performs this calculation.

Legal Obligation & Critical Timing

For returns submitted by 31 October following the tax year end, HMRC is obliged to calculate the tax.

However: If submitted late, HMRC will still calculate on request “but cannot promise to do so before 31 January” following the end of the SA year.

This is a critical policy limitation – like a restaurant warning they can’t guarantee service times for late orders.

What’s Generated

  • Tax Calculation (SA302)
  • Revision Notice (if repairs made) – detailing corrections and reasons
  • Customer Service Messages (maximum 10) – advice on return completion

Delays Can Occur From:

  • Late submission after October 31st
  • Returns requiring extensive repairs
  • Cases needing more than 10 repair/customer service messages (requiring separate correspondence)

STAGE 5: Posting to Main Computer System

What Happens

Information captured in LDC is transferred to the main computer system and “posted” (recorded) to the taxpayer’s permanent record.

Legal Implications

Once posted:

  • Self-assessment becomes official
  • Payment obligations crystallize
  • Interest calculation begins on late payments
  • The enquiry window opens – HMRC has 12 months from receipt date to open compliance enquiries

Infrastructure Issue

This is a batch process, not real-time. There’s a time lag between capture and posting, similar to how banks process transactions overnight rather than instantly.

Delays Can Occur From:

  • System processing cycles
  • Validation errors requiring manual intervention
  • Need to coordinate with other systems (PAYE, payments)

STAGE 6: Generation & Issue of Tax Calculation

What Happens

HMRC sends the taxpayer:

  • Tax calculation showing liability
  • Revision Notice (if repairs made)
  • Statement showing account position

Timing Constraints

For returns submitted:

  • By 30 September (pre-2007-08) or 31 October (2007-08 onwards): Calculation issued with time to pay by 31 January
  • After these dates: Calculation issued but may not arrive before 31 January payment deadline

Policy Rationale

The October deadline exists to ensure taxpayers receive calculations with sufficient time to arrange payment before the 31 January deadline – giving them roughly 3 months’ notice.

Delays Can Occur From:

  • High volumes after October deadline
  • Cases requiring special handling (more than 10 repairs)
  • Postal delays

STAGE 7: Enquiry Window & Compliance Period

What Happens

After posting, HMRC has a 12-month enquiry window starting from the date the return was received.

Legal Framework

  • For 2007-08 onwards: 12 months from date return received
  • For 2006-07 and earlier: 12 months from filing date, or until the quarter date following the first anniversary if filed late

Why This Matters

HMRC can make amendments during this period under Section 9A TMA 1970. After the window closes, changes require:

  • Discovery assessments (more complex legal process)
  • Taxpayer amendments within limited timeframes

Delays in Finalizing Cases From:

  • Returns received just before the enquiry window deadline
  • Cases selected for compliance checks
  • Requests for additional information

Key Infrastructural Limitations Throughout:

  1. Dual System Architecture: LDC operates separately from the main computer, requiring data transfer between systems
  2. Manual Processing Dependency: Unlike online returns, paper requires human data entry
  3. Batch Processing: Updates happen in cycles, not real-time
  4. Volume Sensitivity: October 31st deadline creates processing bottlenecks
  5. Limited Automation: Maximum of 10 repair/customer service messages can be automated; more require manual letters
  6. User Role Requirements: Only staff with specific user roles can process returns, limiting flexibility

Critical Policy & Legal Timeframes:

EventDeadlineLegal BasisConsequence of Missing
Paper return filing31 OctoberSection 8 TMA 1970£100 penalty
HMRC calculation guarantee31 October submissionRevenue obligationNo guaranteed calculation before 31 January
Payment due31 JanuarySection 59B TMA 1970Interest charges, penalties
Repair window9 months from receiptSection 9A TMA 1970Cannot make simple corrections
Enquiry window12 months from receiptSection 9A TMA 1970Limited ability to challenge return

The entire process reflects a tension between thorough manual checking (ensuring accuracy and preventing errors) and processing speed (meeting statutory deadlines). The infrastructure limitations mean that late submissions create a cascading effect – like traffic congestion where each delayed vehicle slows down all those behind it.

How the interest would change if you extended your Time To Pay plan to 12 months instead of 6 (so you can compare total cost vs affordability)

Here’s the 12-month version of your Self Assessment Time to Pay plan so you can see how the interest cost changes compared with the 6-month plan


 Example: 12-Month Time to Pay Interest Calculation

Scenario

ItemDetails
Tax owed£1,500 (balancing payment 2024/25)
Due date31 January 2026
TTP agreed12 monthly instalments of £125 starting 28 Feb 2026
HMRC interest rate7.75 % per year (as of early 2026)

 HMRC’s Method

Interest is simple daily interest on the outstanding balance until each payment date:

{Interest} = {Balance} × 7.75% × {{Days}}{365}

Each payment reduces the balance, so later months accrue less interest.


Month-by-Month Breakdown

MonthPayment dateBalance before paymentDays chargedInterest (£)New balance
Feb 202628 Feb£1,50028£8.91£1,375
Mar31 Mar£1,37531£9.08£1,250
Apr30 Apr£1,25030£7.97£1,125
May31 May£1,12531£7.38£1,000
Jun30 Jun£1,00030£6.37£875
Jul31 Jul£87531£5.76£750
Aug31 Aug£75031£4.93£625
Sep30 Sep£62530£3.98£500
Oct31 Oct£50031£3.29£375
Nov30 Nov£37530£2.39£250
Dec31 Dec£25031£1.64£125
Jan 202731 Jan£12531£0.82£0

Total Interest

£8.91 + £9.08 + £7.97 + £7.38 + £6.37 + £5.76 + £4.93 + £3.98 + £3.29 + £2.39 + £1.64 + £0.82 = \{£62.52}

Total interest = £62.52

So the overall cost is:

[£1,500 + £62.52 = £1,562.52]


Comparison: 6 Months vs 12 Months

Plan lengthMonthly paymentTotal interestTotal costDifference
6 months£250£33£1,533
12 months£125£63£1,563+ £30 interest for 6 extra months

 Takeaway

  • Extending from 6 to 12 months roughly doubles the interest because the balance is outstanding for longer.
  • However, it halves your monthly cash outflow, which may make payments manageable.
  • HMRC accepts longer plans if you can demonstrate affordability — they prefer steady, on-time payments to none at all.

How would I apply for a Time to Pay arrangement: what HMRC asks for and how it affects penalties

Here’s a clear, practical walkthrough of how to set up a Time to Pay (TTP) arrangement with HMRC and what it means for your Self Assessment liability


Time to Pay (TTP) — What It Is

A Time to Pay arrangement lets you spread your Self Assessment tax bill over affordable monthly instalments if you can’t pay it in full by the deadline.

It’s not automatic — you must apply, but HMRC routinely agrees if:

  • You have a good compliance history,
  • The tax debt is temporary (e.g., cash flow issues), and
  • You show that you can keep up with the new payment plan.

Example: Your Case

You owe £1,500 (balancing payment) for 2024/25, due 31 January 2026.
You can’t pay the full amount but could manage £250/month.

You can ask HMRC for a 6-month Time to Pay plan from February to July 2026.


How to Apply

 Online (fastest)

If your circumstances are straightforward, you can do it online:

  • Log into your HMRC online account
  • Select “Set up a payment plan”
  • You can usually do this within 60 days of the payment deadline
  • Must owe < £30,000, have no other payment plans, and your tax returns must be up to date

 HMRC will:

  • Approve automatically (no phone call needed)
  • Confirm the monthly amount and end date
  • Begin collecting payments by Direct Debit

By phone (complex cases)

Call the Self Assessment Payment Helpline:
 0300 200 3822
(Open Monday–Friday, 8am–6pm)

Have ready:

  • Your UTR (Unique Taxpayer Reference)
  • The amount you owe and what you can pay upfront
  • A monthly payment proposal
  • Basic info about your income, outgoings, and savings

HMRC will assess affordability and agree a reasonable plan.


How It Affects Interest & Penalties

TypeWhat happens under TTP
InterestContinues to accrue until the debt is cleared, at the usual HMRC rate (e.g., 7.75%)
Late payment penaltiesPaused once the arrangement is agreed and you stick to it
New penaltiesNone added as long as you keep up payments
DefaultingIf you miss a payment, HMRC can cancel the plan and restart penalties

Example Outcome

You agree to pay £1,500 in 6 instalments of £250 starting 28 Feb 2026.
Interest over 6 months at 7.75% ≈ £44.

Total payable = £1,544 spread over 6 months.

As long as you:

  • Make each payment on time, and
  • File future returns and payments promptly,

No late payment penalties are applied.


Tips for a Successful Plan

  • Offer to pay something upfront (even 10–20%) — HMRC views this positively.
  • Be realistic — it’s better to propose a smaller, sustainable amount than to miss a payment.
  • If your income changes, you can amend the plan by contacting HMRC early.
  • Keep a record of every conversation or confirmation email.

How HMRC calculates the interest during a Time to Pay plan (with the month-by-month breakdown)

Let’s walk through a month-by-month example showing how HMRC calculates interest under a Time to Pay (TTP) arrangement for your Self Assessment balance


Example: Interest During a Time to Pay Arrangement

Scenario

ItemDetails
Tax owed£1,500 (2024/25 balancing payment)
Due date31 January 2026
TTP agreed6 monthly instalments of £250 starting 28 February 2026
HMRC interest rate7.75% per year (Bank of England base + 2.5%)

⚙️ How HMRC Works It Out

  • Interest is charged daily on the remaining unpaid balance.
  • Each time you make a payment, the outstanding balance drops, and daily interest thereafter is calculated on the reduced amount.
  • The formula HMRC uses is:
    [
    \text{Interest} = \text{Balance} × \text{Rate} × \frac{\text{Days outstanding}}{365}
    ]

Payment Plan & Interest Breakdown

MonthPayment dateBalance before paymentDays interest chargedInterest this periodNew balance
Feb 202628 Feb£1,50028 days£1,500 × 7.75% × 28/365 = £8.91£1,250
Mar 202631 Mar£1,25031 days£1,250 × 7.75% × 31/365 = £8.23£1,000
Apr 202630 Apr£1,00030 days£1,000 × 7.75% × 30/365 = £6.37£750
May 202631 May£75031 days£750 × 7.75% × 31/365 = £4.93£500
Jun 202630 Jun£50030 days£500 × 7.75% × 30/365 = £3.18£250
Jul 202631 Jul£25031 days£250 × 7.75% × 31/365 = £1.64£0

🧾 Total Interest Charged

Add the six interest amounts:

[£8.91 + £8.23 + £6.37 + £4.93 + £3.18 + £1.64 = £33.26]

Total interest = £33.26

So your total cost over 6 months is:

[£1,500 + £33.26 = £1,533.26]


Key Points

  • HMRC calculates interest up to the date each instalment is paid.
  • If you pay earlier, interest stops on that amount — so you save money.
  • If you miss or delay a payment, HMRC recalculates interest on the full balance again and may cancel the TTP.

What penalties apply if I miss balancing payments or payments on account?

Let’s build on the same example and show exactly how HMRC charges interest and penalties if you pay late under Self Assessment


Example: Late Payment Interest & Penalties under Self Assessment

We’ll continue with your 2024/25 example:

Type of paymentDue dateAmount
1st Payment on Account31 Jan 2025£6,000
2nd Payment on Account31 Jul 2025£6,000
Balancing Payment31 Jan 2026£1,500

 Step 1 – Interest for Late Payment

HMRC charges daily interest from the day after payment was due until the day it’s actually paid.

  • Rate: Based on the Bank of England base rate + 2.5% (as of 2025, that’s typically around 7.75% per year, but it can change quarterly).

Example:
If you paid your £6,000 July instalment 60 days late and the rate was 7.75%:

[
Interest = £6,000 × 7.75% × \frac{60}{365} = £76.16
]

You’d owe £6,076.16 total.


Step 2 – Late Payment Penalties

Since 2010–11, HMRC applies Late Payment Penalties under Schedule 56 FA 2009 — these are separate from interest.

They apply to any unpaid Self Assessment tax, including balancing payments and payments on account.

Days LatePenalty % of tax unpaid
30 days late5%
6 months lateAdditional 5%
12 months lateFurther 5%

Example:
You didn’t pay your £1,500 balancing payment due on 31 January 2026 until 15 August 2026 — that’s 197 days late.

→ Penalty timeline:

  • After 30 days (2 March 2026): 5% × £1,500 = £75
  • After 6 months (31 July 2026): another 5% × £1,500 = £75
  • Total penalty by payment date = £150
  • Plus interest for ~197 days (~£63 at 7.75%)

So you’d owe £1,713 total (£1,500 + £150 + £63 interest).


Step 3 – Summary

ComponentDescriptionAmount
TaxBalancing payment due£1,500
Interest197 days @ 7.75%£63
Penalties2 × 5%£150
Total payable£1,713

Key Tips

  • Always pay by 31 January and 31 July to avoid both interest and penalties.
  • You can make advance payments or set up a Budget Payment Plan through your HMRC online account.
  • If you can’t pay in full, contact HMRC for a Time to Pay arrangement — this pauses further penalties, though interest still runs.

A numerical example of how self-assessment liability is calculated

Here’s a numerical example showing how HMRC calculates your expected liability under Self Assessment


 Example: Calculating Expected Liability

Background

  • Your total tax and Class 4 National Insurance liability for 2023/24 (after PAYE and other credits) = £12,000.
  • You are self-employed and still trading in 2024/25, so HMRC assumes your next year’s liability will be roughly the same.

Step 1 – Work out the payments on account

Expected liability for 2024/25 is based on 100% of the previous year’s liability, split into two instalments:

[£12,000 × 50% = £6,000 \text{ per instalment}]

  • 1st Payment on Account (POA) – due 31 January 2025 = £6,000
  • 2nd Payment on Account (POA) – due 31 July 2025 = £6,000

You will therefore have paid £12,000 on account by 31 July 2025.


Step 2 – File the 2024/25 tax return

Suppose your actual tax liability for 2024/25 turns out to be £13,500.


Step 3 – Work out the balancing payment

[Actual liability (£13,500)} − \text{Payments on account (£12,000)} = £1,500]

That £1,500 is your balancing payment, due 31 January 2026.


Step 4 – Calculate next year’s payments on account

HMRC will now base your 2025/26 expected liability on this latest figure (£13,500), unless you claim to reduce it.

[£13,500 × 50% = £6,750 \text{ per instalment}]

So your next two payments on account will each be £6,750, due 31 January 2026 and 31 July 2026.


Step 5 – If your income drops

If you know your 2025/26 profits will be lower, you can apply to reduce your payments on account.
For example, if you expect your liability to fall to £10,000, you can claim to reduce each POA to:

[£10,000 × 50% = £5,000]

 If you reduce too much and end up owing more, HMRC will charge interest on the shortfall.


How is the expected liability under self-assessment calculated?

The expected liability under Self-Assessment (SA) is calculated based on statutory guidance outlined in Section 59A and Section 59B of the Taxes Management Act 1970, as referenced in your document.

Here’s how it works:

  1. Starting point – prior year’s liability
    HMRC calculates your expected liability for the current tax year using your previous year’s total income tax and Class 4 NIC liability, less any tax already deducted at source (for example, PAYE or CIS).
  2. Payments on account
    1. You are normally required to make two payments on account, each equal to 50% of the previous year’s net liability.
    1. These are due:
      1. 31 January during the tax year, and
      1. 31 July after the tax year ends.
        These advance payments are meant to cover your “expected” liability for the ongoing year.
  3. Adjustments and balancing payment
    1. Once your Self Assessment tax return is filed, HMRC calculates the actual liability for the year.
    1. The difference between the actual amount owed and what has already been paid on account becomes your balancing payment, due by 31 January following the end of the tax year (Section 59B (1) – (4)).
  4. Reductions or claims
    1. You may make a claim to reduce your payments on account under Section 59A(3) and (4) if you reasonably expect your current year’s income to be lower.
    1. However, excessive reductions made negligently or fraudulently can attract penalties under Section 59A(6).

So in summary:

Expected SA liability = 100% of the prior year’s net income tax and Class 4 NIC liability (excluding tax deducted at source), paid as two equal instalments on 31 January and 31 July.
Any remaining balance is paid the following 31 January once the actual figures are known.

How are partnership appeals dealt with?

Partnership appeals have specific procedures that differ significantly from individual appeals. Here’s how HMRC handles them:

Who Can Make Partnership Appeals

Strict Authority Requirements:

  • Must be made by the nominated partner on behalf of all relevant partners
  • OR by an authorized agent acting for the partnership/nominated partner
  • Appeals from non-nominated partners will be refused
  • Tribunals may reject appeals not made by the nominated partner

Verification Process: If it’s unclear who the nominated partner is, HMRC will:

  • Issue SEES form SA670 to confirm the nominated partner’s name
  • Make a Free Format Note on the Partnership record noting either:
    • “DD/MM/YY SA670 received. Nominated partner is [name]”
    • “YY/YY box 11.3 shows nominated partner as [name]”

Alternative Acceptance: Appeals can be accepted from:

  • Partner shown in box 11.3 on internet-filed returns (current or previous year)
  • Person who signed the paper return (if box 11.3 is empty)
  • Agent acting for all partners (though verification may be needed for large partnerships)

Special Circumstances

Death of Nominated Partner:

  • Successor is generally the person nominated by majority of other partners
  • Must include personal representative of deceased partner in the majority
  • SEES form SA670 must be issued to confirm new nominated partner

Agent Representation:

  • Can accept from agent acting for all partners
  • For large partnerships (hundreds of partners), practical verification may not be possible
  • Issue SA670 to confirm nominated partner details

System Recording Process

Unique Aspects for Partnerships:

  1. Record Location:
    • Appeal recorded only on partnership record
    • Do NOT record on individual partner records
    • Use penalty imposition date as charge creation date (may need to check partner records to find this)
  2. Standover Procedures:
    • Informal standover penalty in full on each individual partner’s record
    • Note work list items: “Working with Partnership, responsible office and UTR”
    • Not necessary to record appeal on individual partner records
  3. Cross-Reference Management:
    • Partner records should note any work list items
    • Include reference to partnership responsible office
    • Maintain clear audit trail between partnership and individual records

Settlement Process

When Appeal is Settled:

  1. Update Individual Records:
    • Where possible, update each individual partner’s record
    • Reduce standovers to nil
    • If direct updating not possible, inform responsible office for each partner
  2. Tribunal Considerations:
    • Ensure tribunal understands they’re considering penalties on all partner records
    • Provide clear documentation of all affected partners
  3. Communication:
    • Notify all relevant offices of settlement outcome
    • Ensure consistent treatment across all partner records

Penalty Application Rules

Late Filing Penalties:

  • All partners charged if partnership return not filed by due date
  • Appeals must go through nominated partner
  • Try to settle immediately if possible

Processing Approach:

  • Handle through partnership record using nominated partner authority
  • Apply informal standovers to individual partner penalties
  • Maintain coordination between partnership and individual records

Administrative Notes

Work List Management:

  • Appeals appear on partnership work list
  • Individual partner standovers noted separately
  • Cross-referencing essential for tracking

Documentation:

  • Retain clear records of nominated partner status
  • Document any changes in partnership composition
  • Maintain audit trail for tribunal purposes

Quality Control:

  • Regular review to ensure all partner records updated
  • Coordinate between multiple responsible offices if needed
  • Monitor for prompt settlement across all affected records

This partnership-specific process ensures that while the appeal is centrally managed through the nominated partner, the practical effects (like standovers) are properly applied to all affected individual partner records, maintaining both legal compliance and administrative efficiency.

What counts as a reasonable appeal for HMRC self-assessment?

A reasonable appeal typically involves either factual grounds or reasonable excuse. Here’s what counts:

Valid Grounds for Appeal

Factual Appeals

  • The assessment, penalty, or charge is factually incorrect
  • The return was actually filed on time
  • Payment was made on time
  • An agreed Time to Pay arrangement was already in place

Reasonable Excuse Appeals

A reasonable excuse is something that prevented the taxpayer from meeting their obligation despite taking reasonable care. It must be based on circumstances outside their control.

What HMRC Typically Accepts as Reasonable Excuse

Health-Related

  • Serious illness preventing the taxpayer from filing/paying
  • Mental health conditions (like PTSD) that impacted decision-making ability
  • Hospitalization that prevented dealing with tax affairs
  • Death of spouse/close relative that significantly impacted ability to meet obligations

External Circumstances

  • COVID-19 pandemic impacts (widely accepted during the relevant period)
  • Fire, flood, or theft that destroyed records or prevented filing
  • Postal service disruption (with certificate of posting showing timely dispatch)
  • HMRC online service failures with error messages as evidence

Technical Issues

  • Computer/software failure just before filing deadline
  • Delayed HMRC activation codes (if requested before deadline)
  • Loss of tax records through circumstances beyond control

What HMRC Does NOT Accept

Explicitly Excluded by Law

  • Shortage of funds (unless due to events completely outside taxpayer’s control)
  • Reliance on another person (unless specific conditions met)

Commonly Rejected Reasons

  • Pressure of work
  • Tax return being “too difficult”
  • Failure by tax agent
  • Lack of information from third parties
  • Not knowing how much tax to pay
  • Absence of HMRC reminders
  • Cheque made out incorrectly
  • Lack of free HMRC software

Key Requirements

  1. Timing: Appeals must be made within 30 days of the notice (37 days allowed for processing)
  2. Writing: Should be in writing, though some telephone appeals accepted
  3. Authority: Must be made by the taxpayer, authorized agent, or (for partnerships) the nominated partner
  4. Prompt Action: Once the reasonable excuse ends, taxpayer must act without unreasonable delay (typically within 14 days)

Special Considerations

  • Each case is assessed on its individual facts and circumstances
  • What’s reasonable for one person may not be for another based on their abilities
  • HMRC considers the taxpayer’s overall ability to manage their affairs during the period
  • Disability may be relevant if it specifically prevented compliance, but existing disabilities require contingency planning

The key test is whether the circumstances genuinely prevented the taxpayer from meeting their obligations despite taking reasonable care, and whether they acted promptly once the excuse ended.

What legislation governs HMRC’s self-assessment infrastructure?

HMRC’s self-assessment infrastructure is governed by several key pieces of legislation:

Primary Legislation

Income and Corporation Taxes Act 1988 (ICTA 1988) – Contains numerous provisions including:

  • Relief calculations for trading losses, farming profits, and personal pensions
  • Post-cessation receipts and literary/artistic profits spreading
  • Relief for losses on unquoted shares

Finance Act 1994 Chapter III – Establishes the foundational self-assessment framework:

  • Personal and trustee returns (Section 178)
  • Self-assessment requirements (Section 179)
  • Partnership returns and assessments (Sections 184-185)

Taxes Management Act 1970 (TMA 1970) – Provides the administrative backbone:

  • Revenue Determinations (Section 28C)
  • Recovery powers for fraud/negligence (Section 29)
  • Error relief provisions (Section 33)
  • Payment on account rules (Section 59A)
  • Balancing payment calculations (Section 59B)
  • Penalty and surcharge provisions (Sections 59C, 93, 93A)
  • Interest calculations (Section 86)

Taxation of Chargeable Gains Act 1992 (TCGA 1992) – Covers capital gains aspects including loss carry-back provisions

Supporting Legislation

Finance Acts 2008 & 2009 – Modern updates including:

  • HMRC set-off powers (FA 2008)
  • Updated interest calculation rules from 2011 onwards (FA 2009)

The Income Tax (Pay As You Earn) Regulations 2003 (SI 2003/2682) – Governs PAYE interactions with self-assessment

This legislative framework creates a comprehensive system covering filing obligations, payment schedules, penalties, interest calculations, and HMRC’s administrative powers for self-assessment.