How to Prepare for Your First HMRC Tax Return
Filing your first tax return with HMRC can feel confusing when you don’t know what to expect. The rules seem complicated and the deadlines come around quickly. The good news is that once you understand the basics and get everything organised early, your first return becomes much easier.
This guide walks you through what to prepare, what HMRC needs from you, and how to avoid the common mistakes that catch people out. Whether you are self employed, a contractor or running a small business, this will help you feel confident and in control.
1. Make sure you are registered with HMRC
If this is your first year of self employment or your first time earning outside a job, you must register with HMRC before you can file a tax return.
You can do this by creating a Government Gateway account and registering for Self Assessment. HMRC will then send you your Unique Taxpayer Reference number.
Without this number, you cannot file.
2. Gather proof of all your income
HMRC wants to see a full picture of what you earned during the tax year.
This includes:
Payments from clients
Money from online platforms
Affiliate income
Ad revenue
Employment income if you also had a job
Bank interest or investment income if relevant
The easiest way is to pull all your bank statements for the tax year or reconcile your bookkeeping software if you use one.
3. Collect your business expenses
Your tax bill is based on your profits, not your total income. So the more accurate your expenses are, the less tax you pay.
Make a list of everything you spent to run your business. Examples include:
Equipment
Software
Travel
Home office use
Phone and internet
Training
Subscriptions
Marketing
Professional services
Keep receipts and invoices. HMRC can ask for them.
4. Check if you can claim capital allowances
If you bought bigger items such as cameras, laptops, office desks or machinery, you might be able to claim capital allowances. This means you claim the cost over time rather than all at once. In many cases the full amount can be claimed in the year you bought it under the Annual Investment Allowance.
This is an area where people often overpay tax simply because they do not know what they can claim.
5. Understand your deadlines
There are two key HMRC deadlines:
The tax year runs from 6 April to 5 April
The filing deadline is 31 January each year
Your tax payment is also due on 31 January
If your bill is over a certain amount HMRC may ask for a payment on account which is a part payment towards next year.
Leaving everything until the last minute is the fastest way to feel stressed and pay more than you need to.
6. Set money aside for your tax bill
A simple way to avoid panic is to put aside a percentage of everything you earn.
For many small businesses, setting aside 20 to 30 percent works well.
This makes your cashflow smoother and stops the January shock that so many people experience.
7. Decide how you will file your return
You can file the return yourself through your HMRC account or use an accountant to handle everything.
If your income is simple and low, you can do it yourself. If you are earning from different sources or want to make sure you do not miss any reliefs or allowances, getting an accountant involved often pays for itself.
8. Double check everything before submitting
Before you press submit make sure:
Your income figures match your statements
Your expenses are correct and supported
You have claimed everything you are entitled to
Your personal details are correct
Any payments on account are understood
A quick final check can save you stress later.
Final thoughts
Your first HMRC tax return does not have to be overwhelming. With the right preparation and someone to guide you, it becomes a simple yearly task that keeps your business running smoothly.
If you want help with your first return or you just want a professional to check everything for you, book a call with me here and I will walk you through everything step by step.