---
title: "Registering with HMRC before your first sale"
description: "Registering with HMRC involves three tasks: Government Gateway login, Self Assessment registration, UTR. Only the second must occur before your first sale."
date: 2026-09-26
lastUpdated: 2026-09-26
author: "Daniel Whitmore"
url: https://storeguides.uk/register-hmrc-before-first-sale/
site: "Store Guides UK (storeguides.uk)"
language: en
---

# Registering with HMRC before your first sale

![A cardboard box, folded canvas bag, coin stack, and tablet rest on a desk, illuminated by purple and blue ambient light.](https://storeguides.uk/images/register-hmrc-before-first-sale-cover-1200.webp)

> **The short answer:** "Registering with HMRC" for online selling is three separate creations: a Government Gateway login, a Self Assessment registration, and your Unique Taxpayer Reference. Only the Self Assessment registration belongs before your first sale. You need to tell HMRC if your income from making or buying things to sell for profit exceeds a certain threshold in a tax year. Selling personal possessions you no longer want does not count as trading, and the £1,000 trading allowance covers everything you sell for profit up to that figure. Do it early, and the platform-data letter HMRC eventually sends reads as a routine confirmation. Do it late, and the same letter reads as an enquiry into a seller who never registered.

Most people searching for this are not asking a software question. They want to know what the taxman expects before money changes hands, and in what order the paperwork falls. This guide walks through the registration sequence in that order.

The broader process of opening a shop is covered in our [Setting up a Shopify shop in the UK: the full guide](https://storeguides.uk/shopify-uk-setup-guide/). Disclosure: some of the Shopify links in this guide are affiliate links. Start a plan through one and this site is paid a commission. What you pay is unchanged. If you sign up through https://www.shopify.com/uk, we are paid a commission, and you pay exactly the same as you would otherwise. This article stays on the HMRC side of the desk.

Shopify plans, pricing and features change; always verify the current details on shopify.com before deciding.

## Table of contents

- [Decide whether you need to register with HMRC before your first sale](#decide-whether-you-need-to-register-with-hmrc-before-your-first-sale)
- [Sole trader, partnership or limited company](#sole-trader-partnership-or-limited-company)
- [The three things "registering with HMRC" actually means for an online seller](#three-things-registering-with-hmrc-actually-means-for-an-online-seller)
- [Register for Self Assessment: the exact steps](#register-for-self-assessment-the-exact-steps)
- [Use your UTR: what to do when it arrives](#use-your-utr-what-to-do-when-it-arrives)
- [Apply the same rules to digital products, dropshipping and print-on-demand](#apply-the-same-rules-to-digital-products-dropshipping-and-print-on-demand)
- [If HMRC's data arrives before you register](#if-hmrcs-data-arrives-before-you-register)
- [Track the dates and numbers that matter after registration](#track-the-dates-and-numbers-that-matter-after-registration)
- [Frequently asked questions](#frequently-asked-questions)
- [Sources](#sources)

## Decide whether you need to register with HMRC before your first sale
The £1,000 trading allowance is the gate. If your income from buying or making things to sell for profit exceeds £1,000 in a tax year, you need to tell HMRC. Below that figure, the allowance covers it and no registration is needed.

Selling unwanted personal possessions is not trading. Clearing out the attic. Selling a guitar you no longer play. Offloading baby clothes your children have outgrown. None of that triggers registration. HMRC's test is whether you are trading, not whether you sold something online.

Trading means buying goods to resell, making goods to sell for profit, or providing a paid-for service. If your plan is to buy stock and sell it on, the £1,000 threshold will not protect you for long. You have a single £1,000 tax-free allowance for all side hustles in each tax year, not a separate allowance per hustle, as HM Revenue & Customs (HMRC), 2025 makes clear.

So the timing question has a simple answer. If your selling plan makes £1,000 inevitable, register before your first sale. If you are genuinely unsure, register once it becomes likely. HMRC also says you must tell them if your total side-hustle income exceeds a certain threshold before expenses.

One edge case. Selling a single personal item or collection for more than £6,000 means you need to tell HMRC, as Capital Gains Tax may be due. That is a different tax on a different event, not a trading test.

## Sole trader, partnership or limited company
Decide the entity before the registration form asks for it.

A sole trader is the default for a side business. You and the business are the same legal person, which keeps the paperwork thin and the registration to a single Self Assessment.

A partnership registers separately and receives its own UTR. Each partner also registers for Self Assessment individually, and a nominated partner takes responsibility for the partnership tax return. More structure, more forms, same threshold.

A limited company starts at Companies House, not HMRC. You incorporate first, then register for Corporation Tax with HMRC within three months of starting business activities. The company files its own return. You still file a personal Self Assessment if you take a salary or dividends.

The decision matters here because it determines whose UTR you are applying for. A sole trader registers their own. A partner registers their own, and the partnership registers a separate one. A company director may need both a personal UTR and a company registration.

For most people opening a first online shop, sole trader is the right starting point. Our [Sole trader or limited company for your shop?](https://storeguides.uk/sole-trader-or-limited-company-uk/) guide walks through the trade-offs in more detail.

## The three things "registering with HMRC" actually means for an online seller
This is where the thesis lands. Most guides say "register with HMRC" and leave it there. Three separate things happen, and only one must precede your first sale.

| What it is | How it reaches you | Need it before your first sale? |
|---|---|---|
| Government Gateway login | Created online, same day | Yes, but only as the front door to the next step |
| Self Assessment registration | Submitted online via GOV.UK | Yes, this is the one that counts |
| Unique Taxpayer Reference (UTR) | Posted within 10 working days | Not the registration itself, but proof it happened |
| Companies House incorporation | Registered online or by post | Only if you are trading as a limited company |

> **Our take:** the Self Assessment registration is the only hard requirement before your first sale. The Gateway login is the same-day front door to it. The UTR is the posted confirmation. Companies House is a different registration for a different business structure. If a guide tells you to "register with HMRC" and means only the Gateway login, you have not sorted the taxman.

The confusion matters because sellers believe they have registered when they have only created an account. The Gateway login gives you access to HMRC's online services. The Self Assessment registration tells HMRC you are trading. The UTR is the ten-character reference that proves the second thing happened.

## Register for Self Assessment: the exact steps
1. Go to the GOV.UK page for registering for Self Assessment. Search "register for Self Assessment" on GOV.UK and follow the link to the registration service.

2. Create a Government Gateway account or sign into an existing one. You will need your National Insurance number, an email address, and a phone number. HMRC sends a verification code by text or by post.

3. Choose "set up as a sole trader" as the reason for registering. HMRC asks why you are registering. This option routes you to the Self Assessment registration for sole traders.

4. Enter your personal details and business information. You provide your full name, date of birth, address, National Insurance number, business start date, and the type of trade.

5. Submit the registration. HMRC confirms on screen that your Self Assessment registration has been received.

6. Wait for two letters by post. The first is your UTR, which is posted within a few working days. The second is an activation code for your online Self Assessment account, posted separately.

7. Use the activation code to access your Self Assessment account online. From here you can file your return when the tax year ends.

Each step states what HMRC sends and in what time. The UTR letter and the activation code arrive by post, not email. If either does not arrive within a reasonable number of working days, contact HMRC and request a resend.

**Suggested registration timeline (our version):**

- **Before listing:** decide your business structure (sole trader, partnership, limited company).
- **Same day:** create your Government Gateway account and submit the Self Assessment registration.
- **By post:** receive your UTR within a few working days.
- **Within a set number of working days:** receive your activation code and activate your online account.
- **By 5 October:** complete registration by this deadline following the end of the tax year in which you started trading.
- **By the deadline:** file your Self Assessment return and pay any tax owed.

## Use your UTR: what to do when it arrives
The UTR is a ten-character reference. HMRC posts it to your registered address within a few working days of your Self Assessment registration.

Keep it with your business records. Quote it in every letter to HMRC, every phone call, and every return you file. It is the reference that ties your name to your tax account.

Never hand it to a customer, a courier, or a marketplace. The UTR is personal tax information. A platform such as [Shopify](https://storeguides.uk/how-shopify-works-uk/) or eBay does not need it. A fulfilment centre does not need it. Only HMRC and your accountant, if you use one, should see it.

Receiving the UTR is the moment "before your first sale" is properly satisfied. The registration is the action. The UTR is the proof. If you have the letter, HMRC knows you are trading. If you do not, you are unregistered regardless of what you clicked online.

If the letter does not arrive, contact HMRC. They can reissue it. You can also find your UTR on previous tax returns or in your personal tax account once activation is complete.

## Apply the same rules to digital products, dropshipping and print-on-demand
HMRC's test is whether you are trading, not what you sell. A digital download crosses the same £1,000 threshold as a parcel of physical goods. A print-on-demand mug does too. The format is irrelevant to the registration.

What changes between these models is record-keeping, not registration. A dropshipping business tracks the cost of goods from the supplier, the platform fees, and the postage paid by the customer. A digital product seller has no postage but may have platform fees and software subscriptions. The records differ. The threshold does not.

A marketplace on a dropshipping model still reports your gross sales to HMRC. The platform reporting rules apply regardless of how you fulfil orders. Your supplier ships the parcel. The platform reports the sale. HMRC sees the data.

The same logic applies to services. If you sell design work, consulting, or online content creation through a platform, the income counts toward the same £1,000 allowance. HMRC's 2025 guidance lists providing services, renting out property, and creating online content alongside selling physical goods.

So the answer is the same across every model. Register for Self Assessment if your trading income from any of these activities will exceed £1,000 in the tax year. The product type does not change the rule.

## If HMRC's data arrives before you register
Platforms such as Amazon, eBay, and Etsy report sellers to HMRC. The reporting trigger is 30 or more sales in a year or revenue above €2,000 (about £1,700), according to HMRC's 2025 guidance. The data-sharing regime stems from DAC7, the EU directive that entered into force on 1 January 2023. The first exchanges of 2023 data happened at the end of February 2024, as documented by the [European Commission's Taxation and Customs Union directorate](https://taxation-customs.ec.europa.eu/taxation/tax-directives-eu/directive-dac7_en).

Being reported does not automatically mean you owe tax. HMRC's guidance is clear on this point. But being reported when you have not registered is a different situation from being reported when you have.

If HMRC holds platform data showing your sales and you have not registered for Self Assessment, the letter you receive will ask why. That is the enquiry scenario. Late registration can trigger penalties that scale with the tax owed, plus interest on the unpaid amount.

If you have already registered and filed, the same data reads as a routine cross-check. HMRC compares what the platform reported against what you declared. The numbers match, and the file closes.

This is the argument for registering before your first sale. The platform data will arrive. Whether it reads as confirmation or as a trigger for an enquiry depends on whether you registered first.

HMRC offers a free online tool to check whether your online income needs to be declared. If you are unsure where you stand, use it. If you are still unsure, contact HMRC or an accountant.

## Track the dates and numbers that matter after registration
The registration deadline is 5 October. HMRC's 2025 guidance says that if you need to tell them about side-hustle income, you must register for Self Assessment as a sole trader. This must be done by 5 October following the end of the tax year in which you started trading.

The filing and payment deadline occurs in late January. Under Making Tax Digital, you must submit your tax return from recognised software by the annual January deadline.

Income tax bands apply to your profits after the £1,000 allowance. You may owe tax if your total income, including your main job, exceeds the personal allowance of £12,570, as HMRC's 2025 guidance states.

National Insurance applies too. Class 2 and Class 4 contributions are calculated on your trading profits, with rates and thresholds set each tax year. Check HMRC's current rates when you file.

Allowable expenses reduce your profit. Common ones for an online seller include stock costs, postage and packaging, platform fees, and [payment processing charges](https://storeguides.uk/uk-payment-methods-shopify/).

Other costs include [software subscriptions including Shopify apps](https://storeguides.uk/shopify-apps-cost-uk/), a portion of home running costs, and business phone and internet use. Keep receipts and records for every expense you claim.

VAT is a separate registration with a separate threshold. You register for VAT when your taxable turnover passes £90,000, according to Stripe's UK VAT guidance. For a new seller, that is some way off. Our [VAT on a Shopify shop: a UK guide](https://storeguides.uk/vat-shopify-uk/) covers it when you get there.

Making Tax Digital for Income Tax arrives on 6 April 2027 if your turnover is above £30,000. It arrives on 6 April 2028 if it is above £20,000, according to [HMRC's 2026 guidance](https://www.gov.uk/government/organisations/hm-revenue-customs). If your turnover is above £50,000, you should already have signed up. A new online reporting tool is due by 2029 for side-hustle income between £1,000 and £3,000, which will replace the Self Assessment return for that band.

The concrete next step: file the return, not just register.

## Frequently asked questions
### Do I need to register with HMRC if I only sell occasionally?

No, if you are selling your own unwanted possessions and not buying to resell. HMRC treats occasional selling of personal items as a disposal, not trading. But if you sell a single item or collection for more than £6,000, Capital Gains Tax may apply and you need to tell HMRC separately under a different process.

### Can I register for Self Assessment before I start selling?

Yes, and it is the sensible approach. HMRC asks for a business start date on the registration form. Use the date you intend to start trading. Registering early means your UTR arrives before you need to quote it, and your online account is ready when the first tax year ends.

### What if I sell on my own website and not a marketplace?

The registration rules are the same. The £1,000 trading allowance and the Self Assessment requirement apply regardless of where you sell. The difference is reporting: a marketplace reports your sales to HMRC automatically, but a standalone website does not. You are still responsible for declaring the income yourself.

### How much National Insurance will I pay on online selling profits?

Class 2 National Insurance is a flat weekly amount, and Class 4 is a percentage of your profits above a lower threshold. The exact rates change each tax year, so check HMRC's current figures when you file. If your profits are below the small profits threshold, you may not pay Class 2 at all.

### What records do I need to keep for HMRC?

Sales invoices, receipts for every expense, bank statements for your business account, and a record of each transaction with date and amount. HMRC expects you to keep these for several years after the 31 January submission deadline. Digital records are acceptable if they capture the same information.

## Sources
1. European Commission — Taxation and Customs Union, "DAC7". https://taxation-customs.ec.europa.eu/taxation/tax-transparency-cooperation/administrative-co-operation-and-mutual-assistance/dac7_en — checked on 27 August 2026
2. Stripe, "What is the UK VAT threshold? What businesses need to know". https://stripe.com/gb/resources/more/what-is-the-uk-vat-threshold-what-businesses-need-to-know — checked on 27 August 2026
3. Stripe, "UK tax compliance: A guide for businesses". https://stripe.com/gb/resources/more/uk-tax-compliance-a-guide-for-businesses — checked on 27 August 2026