Personal tax return preparation and filing
Self Assessment Tax Returns in Cardiff
We prepare Self Assessment returns from the records behind the figures—not from a list of totals without context. Income, gains, reliefs and earlier filings are brought together before you approve the return for submission.
For individuals, sole traders, landlords, company directors and internationally connected clients across Cardiff and South East Wales.
Establish the filing position
Do you need to file a Self Assessment tax return?
A return is commonly required when tax cannot be settled completely through PAYE, when HMRC issues a notice to file, or when income, gains or a charge must be reported. The correct answer depends on the year and the full set of facts.
Check whether HMRC requires a tax return ↗Self-employment, freelance or consultancy income
Turnover, expenses, capital allowances and National Insurance may need to be reported through the self-employment pages.
Rental income from UK or overseas property
Gross rent, ownership, expenses, finance costs and earlier losses determine the property result.
Director income, dividends or taxable benefits
Salary should agree with payroll, dividends with company records and benefits with the information reported by the employer.
Dividends, savings, pensions or chargeable gains
Income outside PAYE and asset disposals may require return pages even where tax has already been deducted elsewhere.
High Income Child Benefit Charge or relief claims
A return may be used to report a charge or claim relief that has not been given fully through a tax code.
A notice to file or an outstanding earlier return
A notice should not be ignored. If the return is not required, the notice normally needs to be withdrawn rather than left unanswered.
The work behind the filing
What our Self Assessment service includes
Submission is the final step. The material work is deciding what belongs on the return, reconciling it to the evidence and showing you how the liability arises.
Filing-scope review
We confirm the tax year, reason for filing, supplementary pages and whether any separate report or earlier correction is needed.
Tailored record request
Your checklist is based on actual income sources, property, gains, reliefs and HMRC correspondence—not a generic document dump.
Income and record reconciliation
Figures are checked against P60s, P11Ds, statements, bookkeeping, rental schedules, disposal records and relevant tax documents.
Relief and allowance review
We consider claims supported by the facts, including pension relief, qualifying expenses, losses, finance costs and foreign tax where relevant.
Tax calculation and payment position
The liability, payments on account and due dates are set out so the amount payable is not confused with the tax calculation alone.
Draft, approval and online filing
You receive the return and calculation for approval. We submit only after questions are resolved and authority to file is given.
You receive a filed return copy, tax calculation and clear payment summary for your records.
How the fee is scoped →Returns are not interchangeable
Self Assessment work for different sources of income
One person can fall into several categories. We prepare the return as a single tax position while directing specialist calculations to the service that owns that work.
Employees, pensioners and individuals with additional income
Employment, benefits, pensions, savings, dividends, relief claims and tax already deducted are reconciled across the year.
Sole traders, freelancers and consultants
We prepare the trading figures, consider allowable expenditure and capital items, and check how the profit affects Income Tax, National Insurance and payments on account.
Landlords and jointly owned rental property
Rental income is prepared from property records with ownership, repairs, finance costs, losses and non-resident status considered separately.
Company directors, founders and investors
Salary, dividends, benefits, director loan issues and investment income are checked against company and personal records before filing.
Foreign income and internationally mobile individuals
Residence, foreign employment, overseas property, pensions, investments, gains and foreign tax credits can require several connected return sections.
Property, share, business and cryptoasset disposals
The annual return may include gains and losses, but a UK residential property disposal can also require a separate report on an earlier timetable.
Live from 6 April 2026
Making Tax Digital has changed Income Tax reporting for some sole traders and landlords
MTD for Income Tax is not simply an annual tax return filed earlier. People within scope must maintain qualifying digital records, send quarterly updates through compatible software and complete the year-end return process.
Check the current MTD for Income Tax requirements ↗Qualifying income is broadly gross self-employment and property income before expenses and tax. Exemptions and special cases require separate checks.
Cardiff and South East Wales
The return should reflect how your income actually arises
Cardiff has a large employed workforce alongside consultants, creative and digital businesses, healthcare professionals, landlords, contractors and owner-managed companies. Their returns often combine sources that are recorded in different places.
A PAYE role may sit alongside consultancy, tutoring, locum work, online sales or other trading income. Tax already deducted must be matched to the correct employment while business records support the separate profit.
Rental income may arise from a Cardiff property while the owner lives elsewhere, or from property outside Wales while the owner is a Welsh taxpayer. Income Tax status and property location answer different questions.
Company payroll, dividends, benefits and loans need to agree with the director’s return. Personal spending and company transactions cannot be treated as one undifferentiated account.
Foreign earnings, overseas accounts, share awards, pensions or disposals can bring residence, exchange rates, foreign tax and Capital Gains Tax into the same filing.
2025/26 filing cycle
Self Assessment deadlines and payments
The return for 6 April 2025 to 5 April 2026 can be filed now. Filing early establishes the liability; it does not normally bring the January payment date forward.
Check current Self Assessment deadlines ↗Notify HMRC if registration is required
Commonly relevant to a first return or a return after a period outside Self Assessment.
Paper return deadline
Different rules apply to certain return types that cannot use the normal online service.
Online return and balancing-payment deadline
The first payment on account for 2026/27 may also fall due on this date.
Second payment on account
Applies where payments on account arise for the following tax year.
Why January can be larger than expected
The amount due is not always the same as the tax shown for one year
A January statement may combine the remaining liability for 2025/26 with the first advance payment for 2026/27. Payments on account are normally based on the preceding year and can sometimes be reduced where the next liability is genuinely expected to be lower. An unsupported reduction can lead to interest.
How payments on account work ↗Evidence before entries
Records needed for a Self Assessment tax return
The exact checklist follows the income and claims. Send source records where possible; a bank statement can confirm payment but may not establish the tax treatment.
PAYE and benefit records
- P60, P45 and relevant payslips
- P11D or payrolled-benefit details
- Pension income and tax deducted
- Employment expense evidence
Income and expense records
- Sales, invoices and bookkeeping
- Bank and payment-platform records
- Rental statements and property costs
- Equipment and capital purchases
Income, gains and foreign tax
- Interest and dividend statements
- Purchase and disposal documents
- Foreign income and tax certificates
- Cryptoasset transaction history
Reliefs and HMRC information
- Pension and Gift Aid contributions
- Student-loan plan information
- UTR and National Insurance number
- HMRC notices and earlier returns
Records must be sufficient to prepare the return and support it if HMRC asks questions. Review the official record-keeping requirements ↗
From records to submission
Our Self Assessment tax return process
You remain in control of the filing. We organise the technical work so every material figure can be followed back to its source.
- 01
Scope the return
We identify the year, sources, gains, reliefs, earlier filings, deadlines and any work outside the annual return.
- 02
Review the records
Documents are organised and reconciled. Missing or inconsistent information is raised before the return is finalised.
- 03
Prepare and explain
We prepare the return and calculation, then explain the liability, payments on account and dates that apply.
- 04
Approve and file
You review and approve the completed return before it is submitted online. The filed documents are then supplied to you.
Late, missing or incorrect returns
Deal with the filing and the reason it went wrong
A late return can involve filing penalties, late-payment penalties, interest and an estimated HMRC determination. An incorrect return may still be within the normal amendment window, while an older error can require a different correction or disclosure route.
Review an earlier tax error →File the correct return without further avoidable delay
Reconstruct the records, distinguish estimates from confirmed figures and check whether several years or taxes are involved.
Read the notice before deciding whether to appeal
The filing date, notice to file, payment history and any reasonable-excuse facts need to be established from evidence.
Use the correct amendment or disclosure route
Do not overwrite one figure without checking how the correction changes tax, interest and payments on account.
A fee based on the actual return
How Self Assessment fees are scoped
A single employment and dividend return is not the same engagement as a return containing business accounts, several properties, foreign income, gains or incomplete earlier records.
The annual return and ordinary tax calculation.
Business, property, foreign income, gains or other supplementary pages.
Whether the figures reconcile or require bookkeeping and reconstruction.
Advice, disclosures, property reports and HMRC correspondence outside routine filing.
Before appointing us
Self Assessment tax return questions
These answers cover the service boundary. Wider informational questions remain on the main tax FAQs page.
Browse all tax FAQs →Can you file my Self Assessment return online?
Yes. Once the engagement and HMRC authority are in place, we prepare the return and calculation, send them to you for review and submit online after receiving your approval.
Can you prepare a return if my records are incomplete?
Often, but the missing information must first be identified and reconstructed where possible. Any provisional or estimated figure must be treated and disclosed correctly rather than presented as confirmed.
Will you tell me how much Self Assessment tax to pay?
We provide the tax calculation and a payment summary showing the relevant balancing payment and payments on account. Your HMRC statement should also be checked for earlier payments, credits, interest or penalties outside the return calculation.
Can you amend a Self Assessment return filed elsewhere?
Yes, subject to reviewing the original return, amendment deadline, supporting records and reason for the change. Older years may require a written correction, claim or disclosure instead of an online amendment.
Do I need a separate landlord or Capital Gains Tax service?
The annual return can contain property and gains pages, but the underlying rental accounts or disposal calculation may be separate work. A UK residential property gain can also have an earlier reporting deadline.
Can you help if I have foreign income?
Yes. We first establish residence, the income or gain, foreign tax, exchange-rate evidence and any treaty point. Complex residence or remittance issues may need separately scoped advice.
When should I provide my 2025/26 records?
As soon as the records are complete. Early preparation leaves time to resolve missing information, understand the January payment and deal with registration or MTD requirements without relying on deadline-week availability.
Start with the full position
Ask us to prepare or review your Self Assessment return
Include the tax year, every source of income or gain, whether a return has already been filed and any HMRC deadline. We will confirm the records and scope required.
Tax dates and MTD thresholds checked against current GOV.UK material on . Personal treatment is confirmed from the facts and records within the agreed engagement.