Small Business Tax Return UK

If you run a small business as a sole trader or work for yourself, Audit Consulting Group can help prepare your Self Assessment tax return, review the information supporting your figures and assist with filing the return with HMRC.

The term “small business tax return” can mean different things depending on how your business is structured. A sole trader normally reports business income through Self Assessment, while partnerships and limited companies follow different filing routes.

Need your return prepared? Send us details of your business, the tax year involved and the records you currently have. We can confirm the appropriate service and scope before work begins.

Get Help With Your Small Business Tax Return

Small Business Tax Return — Quick Facts

Which Small Business Tax Return Do You Need?

“Small business” is not a separate HMRC tax status. The return you need depends primarily on the legal structure of your business.

Sole Trader / Self-Employed

Your business income is normally reported through your personal Self Assessment tax return. This is the primary situation covered by our Small Business Tax Return service.

Self Assessment Tax Return

Partnership

A partnership normally has a separate Partnership Tax Return, while individual partners may also have their own Self Assessment obligations.

If you operate through a partnership, contact ACG so we can establish the appropriate filing requirements and scope before work begins.

Limited Company

A limited company normally files a Company Tax Return for Corporation Tax. This is separate from any personal Self Assessment return that a director or shareholder may need.

Corporation Tax Returns

Important: a Company Tax Return and a director’s personal tax return are not the same filing. Depending on the circumstances, a director may have personal Self Assessment obligations as well as responsibilities connected with a limited company.

If you are unsure which route applies, tell us how your business is structured and we can identify the appropriate service before the engagement starts.

Who Is This Small Business Tax Return Service For?

This service is primarily designed for UK sole traders and self-employed small-business owners who need professional support preparing their annual Self Assessment tax return.

It may be suitable if:

• you run your business as a sole trader;
• you have self-employment income that needs to be reported;
• this is your first tax return as a business owner;
• you have both employment and self-employment income;
• you have several relevant sources of personal income;
• you want an accountant to review the information before the return is filed;
• your filing deadline is approaching;
• you have an outstanding tax return from an earlier year.

If your gross trading income is £1,000 or less, the trading allowance may mean that you do not need to report that income. Exceptions apply, and you may still need Self Assessment for another reason.

This May Not Be the Right Service If…

You may need a different service if you require:

• Self-Employed Registration rather than preparation of the return;
• a Partnership Tax Return;
• Corporation Tax Return preparation for a limited company;
• an amendment to a Self Assessment tax return already submitted;
• bookkeeping support for a sole trader before a return can be prepared;
• personal tax consultation or specialist advice;
• Self Assessment penalty or appeal support.

In these situations, ACG can first identify the relevant service and scope rather than treating everything as part of a standard tax return.

Common Small Business Tax Return Situations

Your First Tax Return

Starting a business does not always make the filing process obvious. You may know that your business income needs to be reported but be unsure what information is required or how your business figures fit into your personal Self Assessment return.

We can establish what information is relevant to the return and identify whether anything important is missing before preparation begins.

If you have not yet registered as self-employed, see our Self-Employed Registration service.

You Have Employment and Business Income

Running a business alongside employment does not mean your PAYE information can simply be ignored. Relevant income sources need to be considered together when preparing your Self Assessment return.

Our Tax Return service covers broader personal Self Assessment filing requirements.

Your Business Records Are Not Fully Organised

A tax return can only be prepared properly from suitable underlying information. If transactions need to be reconstructed, categorised or reconciled first, bookkeeping or record clean-up may need to be separately scoped before the tax return can be completed.

For ongoing record keeping, see our Sole Trader Bookkeeping service.

Your Deadline Is Approaching

If your records are ready, the next step is to establish the scope of the return and provide the relevant information for preparation. If information is incomplete, additional work may be required before the return can be finalised.

Your Tax Return Is Already Overdue

The immediate priority may be getting the required information together and establishing what needs to be filed. Any separate HMRC penalty appeal or dispute should be assessed independently rather than automatically treated as part of tax-return preparation.

If HMRC has already issued a penalty, see our Self Assessment Penalties & Appeals service.

What ACG Does for Your Small Business Tax Return

Our small business tax return preparation service is designed to take the information relevant to your filing, review it and prepare the appropriate Self Assessment return within the agreed scope.

The service includes:

• reviewing the business and personal tax information you provide;
• identifying missing information relevant to preparation;
• reviewing business income supplied for the return;
• reviewing allowable business expenses supplied for the return;
• considering other relevant personal income information provided to us;
• preparing the applicable Self Assessment tax return;
• preparing the related tax calculation;
• raising queries where clarification is required;
• providing the prepared return for your review and approval;
• submitting the return to HMRC;
• providing filing confirmation.

What Is Not Automatically Included?

A standard tax-return engagement does not automatically include every accounting or tax issue connected with your business.

Separate work may be required for:

• reconstructing incomplete bookkeeping;
• correcting historic accounting records;
• multiple outstanding tax years;
• amending previously submitted returns;
• specialist tax planning;
• written tax advice;
• HMRC enquiries or investigations;
• penalty appeals or disputes;
• other work outside the agreed tax-return scope.

Where additional work is required, we will identify it and confirm the additional scope before that work is carried out.

Are Your Records Ready for the Tax Return?

Having transactions in a bank account is not necessarily the same as having records ready for tax-return preparation. One of the first practical questions is therefore whether your business figures are sufficiently organised for the return to be prepared.

If Your Records Are Ready

1. You provide the relevant records and information.
2. ACG reviews the information.
3. We raise questions where clarification is required.
4. Your return and tax calculation are prepared.
5. You review and approve the return.
6. The return is submitted to HMRC.

If Your Records Are Incomplete

1. We identify what information is missing or unclear.
2. We establish whether additional bookkeeping or record clean-up is required.
3. Any additional work is separately scoped where necessary.
4. Tax-return preparation proceeds once suitable information is available.

If your records need work before your tax return can be prepared, see our Sole Trader Bookkeeping service or our broader Bookkeeping services.

What Information Do We Need for a Small Business Tax Return?

The exact information required depends on your business and personal tax circumstances. Not every document below will apply to every client.

Business Income and Records

Common requirements can include:

• business income or sales records;
• invoices or income summaries where relevant;
• records of relevant business expenses;
• business bank statements where required;
• bookkeeping reports or spreadsheets;
• details of relevant business assets;
• details of costs involving both business and personal use where relevant;
• other supporting records relevant to the return.

Other Personal Tax Information

Because a sole trader’s business income is reported through the individual’s Self Assessment return, information outside the business may also be relevant.

Depending on your circumstances, we may need details of:

• employment income;
• dividend income;
• savings or investment income;
• property income;
• pension income;
• capital gains;
• foreign income;
• other taxable income;
• information relevant to applicable reliefs or deductions.

You do not need to guess which documents apply. Once we understand your circumstances, we can confirm what information is required for your return.

If you have more complex personal tax circumstances, you can also use our Personal Tax Consultation service.

Small Business Tax Return Cost

Small Business Tax Return: £200 + VAT.

The standard service includes reviewing the information supplied, preparing your Self Assessment tax return and tax calculation, raising relevant preparation queries, providing the return for your approval, submitting it to HMRC and providing filing confirmation.

Additional fees may apply where your case requires bookkeeping or reconstruction of records, multiple outstanding tax years, amendments to previous returns, specialist tax advice, HMRC correspondence, penalty appeals or other work outside the standard tax-return scope.

Start Your Small Business Tax Return

How Our Small Business Tax Return Service Works

1. Confirm the Scope

Tell us about your business, the tax year involved, your business structure and the main sources of income that may be relevant. We establish whether this is the correct ACG service and confirm the scope before preparation begins.

2. Provide the Relevant Records

You send the business and personal tax information required for your return. If something important appears to be missing, we identify it before final preparation.

3. We Prepare and Review the Return

ACG reviews the information supplied, prepares your Self Assessment tax return and tax calculation, and raises questions where clarification is required.

4. You Review and Approve

You review the prepared return and confirm that the information is complete and accurate to the best of your knowledge before submission.

5. Submission to HMRC

Once the return is approved, ACG submits it to HMRC and provides filing confirmation.

Client, ACG and HMRC Responsibilities

Preparing a tax return involves different responsibilities for you, your accountant and HMRC. Keeping those roles clear helps avoid confusion about what each party controls.

ACG prepares and submits your return, but HMRC controls its own processing, official records, enquiries and decisions.

Small Business Tax Return Deadline

For a sole trader using Self Assessment, the deadline depends on the tax year and how the return is filed.

Online Self Assessment Deadline for 2025/26

The standard deadline for submitting an online Self Assessment tax return for the 2025/26 tax year is 31 January 2027.

Paper Tax Return Deadline for 2025/26

The standard deadline for a paper Self Assessment return for the 2025/26 tax year is 31 October 2026.

Paying Your Self Assessment Tax

Self Assessment tax due for this filing cycle is generally payable by 31 January 2027. Other payment dates can apply in particular circumstances, including where payments on account are required.

First-Time Self Assessment Registration

If you need to file Self Assessment for the first time for 2025/26, HMRC’s general notification deadline is 5 October 2026.

If you need help registering as self-employed, see our Self-Employed Registration service.

Do not leave professional preparation until the filing deadline itself. The time required before submission depends on whether your records are complete and whether questions need to be resolved.

Check Self Assessment deadlines on GOV.UK

Already Missed a Tax Return Deadline?

If your Self Assessment return is overdue, preparing the outstanding return and challenging an HMRC penalty are not necessarily the same service.

Outstanding Tax Return

The first issue may simply be establishing what information is required, preparing the outstanding return and filing it with HMRC.

HMRC Penalty or Dispute

If HMRC has issued a penalty and there may be grounds to challenge it, the appeal should be considered separately on its own facts.

ACG can first establish which work is required rather than assuming that every late return automatically requires an appeal.

Self Assessment Penalties & Appeals

Can You Do Your Own Small Business Tax Return?

Yes. Using an accountant is not automatically a legal requirement for a sole trader’s Self Assessment tax return.

You may choose to prepare the return yourself if your affairs are straightforward, your records are organised and you understand the relevant filing and record-keeping requirements.

When Professional Tax Return Preparation May Be Useful

Professional support may be useful if:

• you have several sources of income;
• your business expenses are more complicated;
• your business records are incomplete;
• you have employment as well as self-employment income;
• you have an overdue return;
• you are unsure which information needs to be included;
• you want an accountant to review the information before filing.

The purpose of professional preparation is not simply to enter figures into a form. It is to establish the relevant scope, review the information supplied, identify questions that need resolving and prepare the return before submission.

What Happens After Your Tax Return Is Filed?

Keep Your Filing Confirmation

Keep confirmation of the submission together with the relevant supporting records.

Pay Any Tax Due

You remain responsible for paying the tax due directly to HMRC by the applicable deadline.

HMRC Processes the Return

HMRC receives and processes the submission and maintains the official tax record.

HMRC May Ask Questions Later

HMRC may later raise questions or open an enquiry. Additional correspondence, enquiry work or representation is not automatically included within the original tax-return service unless separately agreed.

Making Tax Digital for Income Tax and Small Businesses

Making Tax Digital for Income Tax is now relevant to some sole traders and landlords within Self Assessment.

From 6 April 2026, individuals within Self Assessment with qualifying self-employment and property income over £50,000 are required to use Making Tax Digital for Income Tax, subject to the applicable rules and exemptions.

The threshold extends to qualifying income over £30,000 from 6 April 2027 and over £20,000 from 6 April 2028.

Making Tax Digital introduces digital record-keeping and additional reporting requirements, so it should not be treated as simply another name for preparing one annual tax return.

For detailed support, see our Making Tax Digital for Income Tax service.

If you operate as a sole trader, you can also see our MTD for Sole Traders service.

Read the official Making Tax Digital for Income Tax guidance on GOV.UK

Common Problems That Can Delay a Small Business Tax Return

Using the Wrong Filing Route

A sole trader, partnership and limited company do not all file the same return. Establishing the legal structure first helps identify the correct filing route.

Incomplete Business Records

Missing, inconsistent or unreconciled information may need to be resolved before reliable figures can be used in the return.

If this applies to you, our Sole Trader Bookkeeping service may be required before the tax return can be completed.

Leaving Out Other Relevant Income

A sole trader’s Self Assessment return may need information beyond the business itself, including employment, property, investment or other taxable income where applicable.

Waiting Until the Filing Deadline

If information is incomplete or questions need to be resolved, last-minute preparation leaves less time to deal with those issues before submission.

Why Use Audit Consulting Group for Your Small Business Tax Return?

The value of professional tax-return preparation is not simply entering figures into a form.

ACG’s process is designed to establish the correct scope, review the information supplied, identify relevant gaps, prepare the return and distinguish clearly between the work we perform and matters controlled by HMRC.

This gives you a clearer understanding of:

• which filing route applies;
• what information is required;
• what work is included;
• what may require additional work;
• what you need to review and approve;
• what happens when the return is submitted to HMRC.

Expert Insight: The Business and the Taxpayer Are Not Always the Same Thing

A common source of confusion is treating “the business tax return” as one universal document.

For a sole trader, business results feed into the individual’s Self Assessment tax return. A partnership has a separate partnership filing route as well as potential individual partner obligations. A limited company has its own Company Tax Return, while a director or shareholder may separately have personal tax obligations depending on their circumstances.

Identifying the taxpayer and legal structure first is therefore more useful than starting with the general phrase “small business tax return”.

Related Tax and Accounting Services

Self-Employed Registration

If you need to register as self-employed before preparing your first return, see our Self-Employed Registration service.

Tax Return

For broader personal Self Assessment requirements, see our Tax Return service.

Personal Tax Filing

For wider personal tax filing support, see our Personal Tax Filing service.

Corporation Tax Returns

If you operate through a limited company, see our Corporation Tax Returns service.

Sole Trader Bookkeeping

If your business records need to be organised before your return can be prepared, see our Sole Trader Bookkeeping service.

Small Business Bookkeeping

For broader bookkeeping support for a small business, see our Small Business Bookkeeping service.

Amended Self Assessment Tax Return

If a Self Assessment return has already been submitted and needs correcting, see our Amended Self Assessment Tax Return service.

Self Assessment Penalties & Appeals

If the issue involves an HMRC penalty or appeal rather than simply preparing an outstanding return, see our Self Assessment Penalties & Appeals service.

Making Tax Digital for Income Tax

If Making Tax Digital applies to your business, see our MTD for Income Tax service.

Small Business Tax Return FAQs

What tax return does a small business need?

It depends on the legal structure. Sole traders normally report business income through Self Assessment. Partnerships have a Partnership Tax Return route, while limited companies generally file Company Tax Returns for Corporation Tax.

How much does a small business tax return cost?

Our Small Business Tax Return service costs £200 + VAT. Additional fees may apply if bookkeeping, multiple outstanding years, amendments, specialist advice or other work outside the standard tax-return scope is required.

What records do I need for a small business tax return?

Typical information includes records of business income, relevant expenses and supporting business records. Because a sole trader’s business figures form part of the individual’s Self Assessment return, information about other relevant personal income may also be required.

When is the small business tax return deadline?

For a sole trader filing an online Self Assessment return for the 2025/26 tax year, the standard filing deadline is 31 January 2027. Different dates or requirements can apply in particular circumstances.

Can I file my own small business tax return?

Yes. An accountant is not automatically required. Professional support can be useful if your affairs are more complicated, your records need review or you want assistance preparing and filing the return.

Can ACG help if my tax return is overdue?

Yes. We can first assess the outstanding filing and establish what information is required to prepare it. If there is also an HMRC penalty or dispute, that may require separate work. See our Self Assessment Penalties & Appeals service for separate penalty support.

Does a limited company use this service?

Not for its Company Tax Return. A limited company follows the Corporation Tax filing route. A director or shareholder may separately have personal Self Assessment obligations depending on their circumstances. For the company itself, see our Corporation Tax Returns service.

Can ACG submit my tax return to HMRC?

Yes. As part of the agreed Small Business Tax Return service, we can prepare the return, provide it for your approval, submit it to HMRC and provide filing confirmation.

Get Help With Your Small Business Tax Return

If you need a small business tax return prepared, send us some basic information about your circumstances so we can establish the appropriate service and scope.

Please tell us:

• your business structure;
• the tax year involved;
• whether this is your first tax return;
• your main sources of income;
• whether your business records are ready;
• whether any filing deadline has already passed.

We can then confirm the appropriate service, the information required and any additional work needed before preparation begins.

Start Your Small Business Tax Return Enquiry