Self assessment accountant for clear and accurate tax returns

Completing a Self Assessment tax return can feel straightforward until you need to bring together several sources of income, decide which expenses are allowable or understand why HMRC is asking for payments on account.

Asmat & Co Accountants helps individuals, sole traders, landlords, company directors and business owners prepare and submit accurate Self Assessment tax returns. We review your circumstances properly, explain the figures in plain English and make sure you understand what is being reported before your return is sent to HMRC.

Whether your records are already organised or you need help bringing everything together, you receive practical support without unnecessary jargon or last-minute confusion.

Our service can help you:

• Understand whether you need to submit a tax return
• Register for Self Assessment where required
• Organise income and expense information
• Identify relevant allowable expenses and tax reliefs
• Report different sources of income correctly
• Calculate your expected tax liability
• Understand payments on account
• Review your return before submission
• File accurately and on time
• Respond to routine HMRC correspondence

Self Assessment support built around your circumstances

No 2 tax returns are exactly the same.

You may have recently started working for yourself, received rental income alongside your salary, earned dividends from a company or sold an asset during the tax year. You may also have several income streams that need to be reported together on a single return.

We take the time to understand where your income came from, what records you hold and whether there have been any important changes during the year. This gives us the information needed to prepare a return that reflects your actual circumstances rather than treating Self Assessment as a basic form-filling exercise.

Our service is suitable for:

• Sole traders and self-employed professionals
• Freelancers, consultants and contractors
• Landlords and joint property owners
• Company directors receiving dividends or other untaxed income
• Partners in business partnerships
• Individuals with investment or savings income
• People with income from overseas
• Individuals who have sold property, shares or other assets
• People who have received an HMRC notice to file
• Taxpayers who need to correct or bring previous returns up to date

If you run your own business, our sole trader accounting service can also provide ongoing help with bookkeeping, expenses, tax planning and Making Tax Digital.

What is included in our Self Assessment service?

Our work goes beyond entering totals into an online return. We review the information behind the figures so that your income is reported in the correct sections and relevant claims are supported by suitable records.

Reviewing your income

We identify the income that may need to be declared, including:

• Self-employment profits
• Employment income and benefits
• Dividends
• Bank and building society interest
• Pension income
• UK and overseas property income
• Partnership income
• Capital gains
• Foreign income
• Other taxable income

Different types of income can be subject to different tax rules. We make sure each source is reported in the appropriate part of your return rather than combining unrelated figures.

Checking expenses and tax reliefs

Paying the correct amount of tax is not the same as paying more tax than necessary.

Where relevant, we review your records for legitimate business expenses, property costs, pension contributions, charitable donations and other reliefs that may affect your calculation. Every claim must meet HMRC’s conditions, so we focus on expenses and reliefs that can be supported and explained.

We do not make aggressive or artificial claims. Our approach is to apply the available rules properly while protecting you from avoidable errors.

Preparing your tax calculation

Once your information has been reviewed, we calculate your taxable income and expected liability.

You receive a clear explanation of:

• Your total income
• Allowable deductions
• Taxable profit or gains
• Income Tax due
• National Insurance where applicable
• Student loan repayments where relevant
• Payments on account
• The amount and payment date shown by HMRC

Nothing is submitted without your approval. You have an opportunity to review the figures and ask questions before the return is filed.

Submitting the return to HMRC

Once you have approved the completed return, we submit it electronically to HMRC as your authorised agent.

We retain the submission confirmation and let you know how much needs to be paid and when. Where appropriate, we can also help you understand HMRC payment references and how payments on account affect your next tax bill.

When do you need to complete a Self Assessment tax return?

You may need to submit a return if HMRC has asked you to file or if you have received income that has not been fully taxed before reaching you.

Common situations include:

• You earned more than £1,000 in gross income from self-employment during the tax year
• You were a partner in a business partnership
• You received rental income that needs to be reported
• You received significant untaxed income
• You need to report taxable foreign income
• You sold an asset and need to report a capital gain
• You are a company director with dividends or other income that has not been fully taxed
• You need to claim certain tax reliefs through a return
• HMRC has issued you with a notice requiring a return

Receiving a salary through PAYE does not always mean that Self Assessment is unnecessary. You may still need to file if you have rental income, self-employment income, dividends, gains or another source of untaxed income.

We can review your position before preparing a return. This can prevent you from filing unnecessarily or overlooking an obligation that could later lead to penalties.

Self Assessment for sole traders

Your tax return is based on your business income and allowable expenses for the relevant accounting period.

Typical records may include:

• Sales invoices
• Bank statements
• Purchase receipts
• Mileage records
• Equipment purchases
• Software and subscription costs
• Telephone and internet costs
• Professional fees
• Home-working information
• Details of business loans or finance
• CIS deduction statements where applicable

We review the purpose of each cost rather than assuming everything paid from a business account is automatically allowable. Private expenses, capital purchases and day-to-day business costs can all require different treatment.

Where your records need more regular attention, our bookkeeping services can help you maintain reliable information throughout the year instead of rebuilding your accounts shortly before the deadline.

Self Assessment for landlords

Rental income usually needs to be considered alongside your salary, pension, self-employment income and other taxable income.

We can review:

• Rent received
• Letting agent statements
• Repairs and maintenance
• Insurance
• Service charges and ground rent
• Professional fees
• Replacement domestic items
• Mortgage interest and finance costs
• Joint ownership arrangements
• Property losses brought forward
• Capital gains following a sale

Not every property-related payment is treated in the same way. Repairs, improvements, mortgage capital repayments and finance costs can each receive different tax treatment.

Our specialist landlord accountants can help you organise property records, calculate rental profits and understand the wider tax position of your portfolio.

Self Assessment for company directors

Being a company director does not automatically mean that you must submit a Self Assessment return. However, a return may be required when you receive income or gains that have not been fully dealt with through PAYE.

This may include:

• Dividend income
• Benefits received from the company
• Director’s loan transactions
• Income from another business
• Rental income
• Investment income
• Capital gains
• Overseas income

Your personal tax return should also be consistent with your company’s payroll, dividend records and statutory accounts. Our limited company accountants can coordinate your personal and company reporting so that important figures are not considered in isolation.

Important Self Assessment deadlines

The UK tax year runs from 6 April to the following 5 April.

The usual Self Assessment deadlines are:

• 5 October: Deadline to notify HMRC if you need to register for Self Assessment for the previous tax year
• 31 October: Deadline for submitting a paper tax return
• 30 December: Deadline for an online return if you want HMRC to consider collecting eligible tax through your PAYE code
• 31 January: Deadline for submitting an online tax return and paying the tax due
• 31 July: Deadline for the second payment on account where payments on account apply

You do not have to wait until January to complete your return. Filing earlier can give you more time to understand the calculation, prepare for the payment and resolve missing information.

Understanding payments on account

Payments on account often surprise people when they complete their first return with a significant tax bill.

They are advance payments towards your next Self Assessment liability. Each payment is normally based on half of the previous year’s qualifying tax bill, with instalments generally due on 31 January and 31 July.

This can mean that your January payment includes:

• The balancing payment for the tax year just completed
• The first payment on account towards the following tax year

Payments on account do not normally include amounts such as Capital Gains Tax or student loan repayments.

Where you reasonably expect your next tax liability to be lower, it may be possible to apply to reduce the payments. However, reducing them too far can result in interest being charged, so the estimate should be based on reliable information rather than guesswork.

What happens when a tax return is filed late?

HMRC can issue an initial £100 late-filing penalty when an online tax return misses the 31 January deadline. This penalty can apply even when there is no tax to pay.

Further penalties can build up when a return remains outstanding. Separate penalties and interest may also apply when tax is paid late.

Submitting the return as soon as possible is usually the best way to prevent the position from becoming more expensive. We can help prepare overdue returns, identify missing records and explain what needs to be done to bring your affairs up to date.

Preparing for Making Tax Digital for Income Tax

Making Tax Digital for Income Tax began on 6 April 2026 for qualifying sole traders and landlords.

You are generally required to use the system from:

• 6 April 2026 if your qualifying income for 2024/25 was more than £50,000
• 6 April 2027 if your qualifying income for 2025/26 was more than £30,000
• 6 April 2028 if your qualifying income for 2026/27 was more than £20,000

Qualifying income broadly means your total gross income from self-employment and property before expenses are deducted.

Where the rules apply, you will need to:

• Keep digital accounting records
• Use compatible software
• send quarterly updates to HMRC
• Complete the required year-end information
• Finalise your overall tax position

We can check whether the rules apply to you, help organise your digital records and manage the reporting process. Preparing early is particularly important if you currently rely on paper records, spreadsheets that are not digitally connected or a single annual review of your transactions.

What information will we need from you?

The documents required depend on your sources of income.

You may need to provide:

• Your Unique Taxpayer Reference
• National Insurance number
• P60 and P45 forms
• P11D benefits information
• Business income and expense records
• Bank interest certificates or statements
• Dividend vouchers
• Pension statements
• Property income and expense records
• Partnership statements
• Details of assets sold
• Pension contribution information
• Gift Aid donation records
• Student loan details
• Foreign income and tax information
• Details of previous payments on account
• Relevant correspondence from HMRC

Do not delay speaking to us because a document is missing. We can help identify what is required and explain where the information may be available.

Why choose Asmat & Co Accountants?

Asmat & Co Accountants has supported individuals and UK businesses since 2007. Our team includes ACCA, CIMA and IFA-qualified professionals with practical experience across personal tax, business accounts, property income and HMRC reporting.

You benefit from:

• Experienced and professionally qualified accountants
• Advice based on your actual circumstances
• Clear explanations before submission
• Support with several income sources
• Careful review of expenses and reliefs
• Digital and Making Tax Digital support
• Fixed-fee options with transparent pricing
• Help communicating with HMRC
• Ongoing support beyond the filing deadline
• Secure online service for clients across the UK

We focus on getting the return right while helping you understand the figures. You should know what has been reported, why tax is due and what you need to prepare for next.

How our Self Assessment service works

Initial review

We discuss your income sources, employment, business activities, property, investments and any relevant changes during the year.

Registration and authority

Where necessary, we help you register and obtain authority to deal with HMRC as your accountant.

Information collection

We provide a clear list of the documents and records required for your return.

Preparation and review

We prepare the return, check the supporting information and calculate the tax position.

Your approval

We explain the key figures and send the return to you for approval.

Submission and payment guidance

Once approved, we file the return and confirm the amount and payment deadline.

Ongoing planning

Where appropriate, we help you improve record keeping, budget for future liabilities and prepare for Making Tax Digital.

Get your Self Assessment under control

Avoid leaving your tax return until records are missing and the deadline is approaching. Speak to our team for clear advice, accurate preparation and dependable support with your Self Assessment.

Frequently asked questions

Do I need a self assessment accountant?

You are not legally required to use a self assessment accountant. You can prepare and submit your own return if you understand the requirements and have straightforward, complete records.

Professional support can be valuable when you have several income sources, business expenses, rental properties, capital gains, foreign income, missing records or uncertainty about what must be reported. An accountant can also save you time, review relevant claims and reduce the risk of avoidable mistakes.

How much does an accountant charge for a Self Assessment tax return?

The cost depends on the complexity of your return and the quality of your records. A return covering a single straightforward income source will usually require less work than one involving self-employment, property income, dividends, capital gains or overseas income.

Asmat & Co Accountants provides a clear quote after reviewing the work required, so you know the fee before proceeding.

What documents does an accountant need for Self Assessment?

Your accountant may need your P60, P45, P11D, business records, bank interest, dividend information, pension details, property statements, investment records and information about assets sold.

The exact list depends on your circumstances. It is helpful to provide HMRC correspondence and details of any previous payments on account as well.

Can an accountant submit my Self Assessment tax return for me?

Yes. Once you authorise an accountant to act for you, they can prepare the return, send it to you for approval and submit it electronically to HMRC.

You remain responsible for making sure the information you provide is complete and accurate. A reputable accountant will explain the figures and obtain your approval before filing.

What happens if I miss the Self Assessment deadline?

HMRC can issue an initial £100 penalty for a late online return, even when you do not owe any tax. Further penalties may be charged if the return remains outstanding, while late payment interest and separate payment penalties may apply to unpaid tax.

You should submit the return and address the outstanding payment as soon as possible. An accountant can help organise missing information, prepare the overdue return and explain the steps required to bring your tax affairs up to date.