Self Assessment tax return to complete? Keep it simple…

5 Minute Read

Last Updated: 3rd March 2025

The KISS principle. You may well have heard of it. If not, KISS stands for “Keep it simple, stupid!”, a design principle thought to have been coined by a lead aviation engineer working for the US military in the 1960s.

The KISS principle encapsulates the idea that things often work best if they’re kept simple, which is why simplicity should always be a key goal. Making things more complicated than necessary is crazy, when simple is usually best.

Making tax simple

The desire to keep things as simple as possible was the key guiding principle when we created GoSimpleTax more than a decade ago – so much so, in fact, that we included the word simple in our name.

Simplicity is a hugely attractive proposition when it comes to completing a Self Assessment tax return, but in what ways does our software actually make things simple and why use it as opposed to filling in and filing your Self Assessment tax return via HMRC’s online services?

Simple to register

It’s remarkably simple to sign up for a GoSimpleTax user account. Many users tell us they much prefer the look and feel of GoSimpleTax when compared to the HMRC online option, and as a result they find it easier to complete the process.

If you use tax software, it’s simple, quick and painless to get the summary figures you need from your taxable business or landlord income. And with GoSimpleTax you don’t need to worry about whether you’ve filled in the right supplementary pages to include with your main SA100 tax return. All you need to do is specify the sources of your taxable income and GoSimpleTax will load up the necessary supplementary pages for you. What could be simpler?

Simple language

You’ll then be guided through your tax return and asked to input figures, which will automatically appear in the correct part of your tax return. Automatic prompts are there to help guide you through, using accessible, plain English language, not tax jargon. With all of the necessary facts and figures to hand, it should be possible to complete and file your tax return in a couple hours or less (without GoSimpleTax the process could take much longer).

It’s unlikely, but if you get stuck, GoSimpleTax comes with responsive email support, praised by many users, ensuring that you’re not left hanging on the telephone for hours. All of our team are highly trained tax professionals with many years of experience.

Simple guidance

GoSimpleTax provides embedded hints and tips on potential tax savings, which could help you to save money on your current and future Self Assessment tax returns. It’s also designed to ensure that you input all of the necessary information in the right place, which reduces the risk of (possibly expensive) mistakes. It’s always best to get it right the first time.

Another key selling point for GoSimpleTax is it gives you peace of mind, because you’re not left worrying for weeks or months that your tax return contains mistakes that HMRC will later contact you about, which could cost you time and money.

HMRC online tax services

Not everyone can use HMRC’s online services to file their annual Self Assessment tax return online. The system does not accept returns from all UK taxpayers. This includes those who live overseas and are registered as non-resident for tax, but who earn UK-taxable income (often from renting out property in the UK). Paying a UK-based accountant to do it for you could cost you a few hundred pounds or more. 

You cannot use HMRC’s online services to file a tax return for a trust or estate or to report multiple “chargeable gains” (eg from life insurance). And if you’re a Lloyd’s underwriter or religious minister, you cannot file a tax return by using HMRC’s online services. What most choose to do, if they want to do their own tax return, which is the far cheaper option, is to use commercial Self Assessment tax return software, such as GoSimpleTax.

HMRC publishes detailed guidance online on how to fill in an SA100 and supplementary pages, but some people struggle to understand it, plus they won’t necessarily prevent you from leaving out information, inputting it into the wrong box or making other simple mistakes. GoSimpleTax makes this much less likely, which could save you lots of time and money.

Life is complicated enough, why not go for the simple option? GoSimpleTax makes it easier, quicker and cheaper to fill out and file your tax returns. Start your FREE trial today to find out why thousands of other people like you simply love GoSimpleTax.   

Trusted by over 20,000 subscribers

You don't need to be an expert to complete your Self Assessment tax return.

Find Out More

Blog content is for information purposes and over time may become outdated, although we do strive to keep it current. It's written to help you understand your Tax's and is not to be relied upon as professional accounting, tax and legal advice due to differences in everyone's circumstances. For additional help please contact our support team or HMRC.

5 Excellent Reasons to Choose Us to File Your Tax Return

Discover how to make tax returns a doddle...

Find out more

Why it could pay to get ready now to file your tax return in April

03 Mar 2025

The chances are that because you’ve just gone through the process of completing and filing one, you’ve had quite enough of Self Assessment tax…
READ MORE >

Alternatives to an accountant completing your Self Assessment tax return

14 Feb 2025

Very few people enjoy filling in tax returns. It would be rather odd if they did. Completing a Self Assessment tax return is something…
READ MORE >

Correcting mistakes in a Self Assessment tax return after you’ve filed

10 Jan 2025

We all make mistakes, don’t we? Normally they’re minor mistakes and we’re able to correct them immediately or very soon after we’ve made them,…
READ MORE >

How GoSimpleTax Works

01.
Register

Simply register for free with your full name and email address.

02.
Select Your Income

Select the income you receive and follow the hints and tips for potential tax savings.

03.
Validate Your Information

Validate your personal information and submit directly to HMRC to get confirmation in just seconds.

ipad

Work Anywhere, With Any Device

Gone are the days of fretting over a calculator surrounded by scraps of paper at the eleventh hour.

GoSimpleTax’s tax return software uses the information you upload in real time to calculate your income and expenditure, working out the tax you owe and sending you helpful notifications when there’s the possibility of a mistake.

Start your free trial

"The software is intuitive and proved very easy to navigate. I found the whole process refreshingly simple. I saved a lot of money too!"

Steve J.

Ordained Presbyter

"Easy to use and value for money. Everything you need to do your tax."

Gordon J.

Self Employed

"It fills in all the forms and sends them to the Inland Revenue. Not expensive either. Takes the stress out of doing your tax return online."

Ross G.

Team Rector

Why use GoSimpleTax over HMRC >