ATA · PERSONAL TAX & SELF ASSESSMENT
Self Assessment Accountants London
Clear tax returns, sensible advice and fewer surprises at the deadline.
Our Self Assessment Accountants London service supports sole traders, landlords, company directors and people with multiple income sources. We help bring your figures together, identify relevant reliefs, prepare your return and explain the tax due.
UK-wide online support · London-based accountancy practice
WHO WE HELP
Who may need a Self Assessment tax return?
Not everyone needs to file. But certain income, gains and circumstances make a return necessary, and HMRC may also issue a notice requiring one.
Sole traders & freelancers
Self-employed people with more than £1,000 gross trading income, subject to HMRC’s rules and exceptions.
Landlords & property owners
Rental income, property expenses, jointly owned property and UK property tax reporting.
Property accounting support ↗Company directors & shareholders
Dividends, benefits, other income or circumstances requiring personal tax reporting. Directorship alone does not automatically mean a return is required.
People with investment income
Dividends, savings, capital gains and multiple income streams that may need reporting.
Capital Gains Tax support ↗Construction subcontractors
CIS deductions, allowable costs and possible repayment claims through Self Assessment.
CIS tax refund guidance ↗People with foreign income
Overseas employment, property, investments or other cross-border matters requiring additional consideration.
Unsure whether you must file? Use HMRC’s official eligibility guidance or ask us to review your circumstances.
WHAT ATA DOES
How our Self Assessment Accountants London service helps
More than just submitting an SA100: we organise the underlying records and explain the outcome before filing.
Registration & UTR guidance
Help identifying whether you need to register, re-register or deal with an HMRC return notice.
Income and expense review
Reconcile trading, rental, employment, dividend and interest figures using appropriate records.
Reliefs & allowances
Review relevant expenses, allowances and tax reliefs where supported by your circumstances.
Return preparation & submission
Prepare applicable return sections, share the figures for approval and submit to HMRC where authorised.
Tax calculations & payments on account
Explain the balancing payment, potential payments on account and what may be due next.
Late returns & corrections
Help you understand missing returns, amendments, notices and practical next steps.
SIMPLE PROCESS
From scattered paperwork to a completed return
Tell us about your income
We establish your tax year, income sources, filing history and the work required.
Send your records securely
We request relevant documents and flag missing information early.
Review the calculation
We prepare the return and explain the proposed figures and tax liability.
Approve and file
After your approval, we submit the return where engaged and authorised.
GET READY
What documents will you need?
What we request depends on your return. You do not need every item below.
- UTR, National Insurance number and prior-year return, if available
- P60, P45, P11D or pension statements, where relevant
- Business income, invoices, expenses and bank records
- Rental income and property expenses
- Dividend, interest and investment statements
- Capital gains, foreign income or other supporting schedules
File early, even if payment is later
Preparing the return before January gives you more time to check the figures and plan for the tax payment. Filing early does not normally bring the standard payment deadline forward.
HMRC: sending a return ↗LOOKING AHEAD
Making Tax Digital for Income Tax
Making Tax Digital (MTD) is changing record keeping and reporting for many sole traders and landlords. Qualifying taxpayers may need compatible software and quarterly updates in addition to end-of-year processes.
Implementation is phased based on qualifying income from self-employment and property. ATA can help assess whether your business is affected and what records need to change.
Read HMRC’s MTD eligibility guidance ↗Current rollout thresholds
FREQUENT QUESTIONS
Self Assessment FAQs
Do I need a Self Assessment return if I am a company director?
Being a director does not automatically create a filing obligation. Whether you need a return depends on your income, gains, HMRC notices and other circumstances.
What is the deadline for the 2025/26 tax return?
Normally, online returns and the balancing payment are due by 31 January 2027. The usual paper return deadline is 31 October 2026. Different deadlines can apply in limited circumstances.
Can ATA prepare my return if I have more than one income source?
Yes. We can review a combination of employment, trading, property, dividends, savings and other income, subject to agreeing the scope and any specialist input needed.
Can CIS deductions result in a refund?
Possibly. CIS tax deducted is credited against the final tax position. A refund depends on the full calculation, including other income and liabilities; it is not guaranteed.
What are payments on account?
They are advance payments towards the next year’s Self Assessment bill in cases where HMRC’s rules require them. We explain their calculation and whether a reduction claim may be appropriate.
What if I have missed a filing deadline?
Contact us promptly. We can review the outstanding return, possible penalties and interest, and options for dealing with HMRC.
Does Making Tax Digital replace Self Assessment?
It changes how affected individuals keep and submit certain income records, but an annual tax return and the usual tax payment deadline remain part of the process.
TALK TO ATA
Need help with your Self Assessment?
Tell us which tax year you need, what income you receive and whether your return is already overdue. We’ll discuss the work involved and the next steps.