Self Assessment software

Get your Self Assessment Crunched conveniently

Self Assessments can be royally painful. Not any more.
Welcome to Crunch Self Assessment, possibly the easiest and most cost-effective service out there!

A standalone service that combines a beautifully easy online application, with the absolute reassurance of a trained accountant checking your return.

image of a man filing his self assessment

Cernat David Si Denis

Crunch are simply amazing. I am very happy that I switched to Crunch a few months ago.  


I have been using Crunch Accounting since 2014. Every time I have needed something, no matter how obscure, they have been super helpful and efficient.


I am grateful for the detail of support Crunch have given me over the years, and especially today. I cannot imagine using any other service.

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What is a Self Assessment?

What is
Self Assessment?

Self Assessment is HMRC’s calculation of the Income Tax and NI needed to pay

Employees have their Income Tax automatically deducted from their employment income through the PAYE system.

This does not happen for self-employed workers, which is why the Self Assessment is required.

You are legally required in the UK to register for and file a Self Assessment with HMRC by 31 January annually.

You need to file a Self Assessment for other types of income such as dividends, pension, income from savings and investments plus being a landlord.

Explore our How To Complete a Self Assessment article.

Speak to a specialist

Why choose Crunch Self Assessment?

Crunch's intuitive software is supported by our award-winning Customer Service team and Chartered Certified accountants

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Standalone service

Crunch doesn't tie you to long-term commitments. This is a standalone service that can be used just once or as often as you want.

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One-off fee

Crunch's qualified accountants and administration team will complete a Self Assessment, and file it with HMRC, for a one-off fee of £95+VAT.

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Examined by an accountant

Crunch’s qualified accountants are extremely thorough. They will check every Self Assessment before these are filed with HMRC.

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Last-minute assistance

Crunch can complete and file your Self Assessment within three working days of your deadline. No need to panic because Crunch can ride to your rescue.

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Reported to HMRC

Crunch prepares all of the relevant information for HMRC. We just ask you a series of questions then get on with the task in hand.

When do you need to file a Self Assessment?

Everyone should complete a Self Assessment if receiving income where the tax is not deducted at source,

For example, the income received from operating as a Sole Trader or working as a Limited Company director does not have NI contributions nor Income Tax already deducted. The HMRC needs to be informed about that income on a Self Assessment form to calculate whether tax should be paid.

Crunch can advise and guide professionals through the potential minefield of Self Assessment filing.

Examples of professionals who are required to file a Self Assessment:

Air BnB Hosts
First time tax filers
Sole traders
CIS Subcontractors
High earners (£100k+)
Company Directors
People Living abroad

Explore our How To Complete Self Assessment article.

How we Crunch your Self Assessment

Crunch's service means no errors. Despite users being armed with easy-to-use software, we use the safety net of fully-trained accountants to check your return before it is filed.

smartphone mockup on self assessment page


Disclose basic information

Answer a handful of questions about your business transactions, which can be saved as they are filled in online.


Crunch will figure it out

Crunch's qualified accountants are renowned for spotting any incorrect or missing information. We will get back to you to clarify the figures.


Count on Crunch

Our proficient team of fully-trained accountants guarantee to make your business as tax-efficient as possible.

smartphone using Crunch software

Crunch Self Assessment just £95+VAT

Crunch has long-built a reputation for affordable, innovative and easy-to-use products.


Crunch Self Assessment

Our full software and service version of Crunch Self Assessment is available for a flat fee.


one off payment
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Sole Trader or Limited Company?

Whether you operate as a Sole Trader or run a Limited Company you could benefit from Crunch’s award-winning Premium services, where our Self Assessment is included free-of-charge.

Explore Crunch Self Assessment
Pay a one off fee of just £95 plus VAT

Frequently asked questions about Crunch's Self Assessment service

What is a Self Assessment?


Self Assessment is HMRC’s way of finding out how much Income Tax and National Insurance Contributions you need to pay. Employees have these taxes deducted automatically from their employment income through the PAYE system – this doesn’t happen for self-employed workers, or for some other types of income, such as dividends, pensions or income from savings and investments, which is where the Self Assessment comes in.

For more information, check out our “What is Self Assessment?” article.

Who needs to do a Self Assessment?


As a general rule, anyone who receives income that isn’t taxed at source needs to complete a Self Assessment.

If you’re a sole trader, the income you receive from your trade doesn’t have National Insurance Contributions or Income Tax deducted from it, so you need to tell HMRC about that income on a Self Assessment form so they can calculate what, if any, tax you owe.

If you’re a limited company director, you’ll usually need to file a Self Assessment to let HMRC know about any dividend income you’ve received from your company. Check out our “Do I have to file a Self Assessment?” article for all the details.

How to register for Self Assessment?


You’ll need to register with HMRC to tell them you need to submit a Self Assessment. You must enrol for Self Assessment by 5th October after the end of the tax year for which you are required to file a tax return – for example, if you need to file a Self Assessment for the 2020/21 tax year, you should register by 5th October 2021. If you miss this deadline, you may have to pay a penalty.

You can register online, by post or by phone – always make sure you give yourself enough time in case anything goes wrong. To register, you’ll need your:

  • National Insurance number
  • Personal and business details.

After you’ve registered, HMRC will send you a Unique Taxpayer Reference (UTR) number in the post. You use your UTR to register for HMRC Online Services. HMRC will then send you a PIN number in the post to access Online Services where you can file your Self Assessment. Once you’ve registered once, you won’t have to register again.

How do I pay any Self Assessment tax I owe?


Once you’ve submitted your Self Assessment, HMRC will tell you how much tax you owe. You’ll usually make your payment via Direct Debit or bank transfer.

Can I do my own Self Assessment?


If you’d like to, you can prepare and file your own Self Assessment with HMRC, but we would strongly recommend you seek professional support from an accountant like Crunch. Even the tiniest inaccuracy can cause a major headache further down the line, so enlisting the support and experience of a professional accountant to file an accurate Self Assessment is vital.

Do I need an accountant for Self Assessment?


You’re under no legal obligation to hire an accountant to file your Self Assessment, but their experience and expertise makes an accountant an invaluable asset.

Do I need a Crunch subscription to submit a Self Assessment?


At Crunch, you can file your Self Assessment with us using our Crunch Free account. Our Self Assessment product is a standalone service, and for a one-off fee of £95+VAT (or £200+VAT after 1st December), our Chartered Certified accountants can file your return on your behalf.

This Self Assessment service is included in our Sole Trader Pro and Limited Company Small Business packages, too.

How much does the standalone Crunch Self Assessment service cost?


Our Self Assessment product is a standalone service, and for a one-off fee of £95+VAT, which increases to £200+VAT after 1st December. 

All you need to do is open a Crunch Free account and purchase our Self Assessment service. As the name suggests, opening and running your Crunch Free account costs you absolutely nothing!

Can I give my own accountant access to Crunch to submit my Self Assessment?


If you’re a Crunch Free client, you can give your own accountant access to your account so that they can file your Self Assessment on your behalf. 

If you’re a Crunch Sole Trader Pro, Limited Company Pro, Premium, or Small Business client, Crunch are your accountants, so you won’t be able to (or need to!) share your information with another accountant.

When is a Self Assessment due?


Your Self Assessment must be filed ahead of HMRC’s 31st January deadline each year. You can file yours any time after 6th April; we highly recommend you file your Self Assessment at the earliest possible opportunity.

How long does a Self Assessment tax return take?


There are a lot of factors that can impact the length of time it takes to complete a Self Assessment. If you’re filing it by yourself, it could take less than an hour using HMRC’s online service. If your personal tax affairs are complex, with information needed from various sources and allowances to claim, it may take days or even weeks depending on how accurately you’ve maintained your records.

At Crunch, we aim to complete your Self Assessment within six weeks of your request.

Do I need approved software to submit my Self Assessment?


As of right now, Self Assessment tax returns are not subject to HMRC’s Making Tax Digital (MTD) scheme. MTD is being introduced for some taxpayers, such as landlords and the self-employed, from 2024. You can find out more in our ITSA article.

Is an online Self Assessment easy?


Self Assessments can get complicated if you’re new to the process, or if you’re filing your Self Assessment by yourself. Getting an accountant to do it for you can make the process much simpler, especially if you’ve kept accurate, up-to-date records in your online accounting software.

How much does a Self Assessment cost?


At Crunch, we offer a Self Assessment service on our Crunch Free and Limited Company Pro packages from a simple, flat fee of £95+VAT, no matter how complex your return is. This price increases to £200+VAT from 1st December. 

Self Assessment filing is included as part of our Crunch Sole Trader Pro, Limited Company Premium, or Limited Company Small Business packages.

How much do accountants charge for Self Assessment in the UK?


On average, a UK accountant will charge you anywhere between £150 to £250 (or potentially more!) to prepare and file your Self Assessment, depending on the complexity of your return. That makes Crunch one of the most cost-effective Self Assessment solutions for UK small business owners.

Can I get a copy of my Self Assessment?


By logging into HMRC’s online services, you can access your previously filed Self Assessments, where you’ll have the option to print your documents. You may require a copy of your Self Assessment for mortgage applications and other checks.

Where do I send a Self Assessment tax return?


When you’ve registered with HMRC and received your Unique Taxpayer Reference (UTR) code and log-in details, you can access your HMRC account. From there, you can file your Self Assessment.

If you’re a Crunch client, we can file your Self Assessment with HMRC on your behalf. All you need to do is approve the return we prepare for you, and we’ll do the rest!

How to deregister for Self Assessment?


You can deregister for Self Assessment if you’re no longer self-employed. You can call HMRC on 0300 200 3310 and inform them you’re no longer self-employed, or you can simply deregister online.

You’ll need the following to hand:

  • Your National Insurance Number
  • Unique Tax Reference (UTR).

How long does it take to get a tax refund after Self Assessment?


If you’re entitled to a tax refund from your Self Assessment, you should allow four weeks for your refund to be sent to your bank account.

If any tax is due within 35 days of your Self Assessment submission (for instance if a payment on account is due), you may not receive a refund. The money may instead be deducted from the tax you owe.

How does HMRC contact me and what about scams?


HMRC will usually send you information about your Self Assessment by post. This includes information about any rebates or amounts to be paid by post, so you must ensure your details are kept up-to-date on your online account. 

Occasionally, you may receive a text reminder if you're due to file your Self Assessment. HMRC will NEVER contact you by phone or text regarding a tax rebate or refund, or to ask for personal or financial information. 

HMRC don’t use a pre-recorded message asking you to transfer money and threatening legal action. If you’re in any doubt about a call, email, or text, it’s probably a scam. Always check your online account and you’ll see if you owe any money or not. You can find out more about scams on HMRC’s website.

Self Assessment filing can be baffling. Count on Crunch.

Crunch boasts over a decade of experience by assisting a plethora of businesses with professional advice and guidance from experts.

Our Knowledge articles, jargon-free business guides, tools and calculators as well as tutorial videos can help answer your questions.

Our free self-employed community, Crunch Chorus, boasts over 71,000 members like you.