Registering a company: Key things you need to know

Self-employed tax deadlines you need to know

Timing is everything when it comes to tax. Miss a deadline and you risk penalties that can escalate quickly.

Here are the key dates for your 2025 diary:

• 5th April 2025 - The end of the 2024/25 tax year is the last day you pay tax on income earned in that tax year
• 6th April 2025 - The start of the 2025/26 tax year is the first day you’ll pay tax on income earned in the next financial year
• 31st July 2025 - Second payment on account due
• 5th October 2025 - Deadline to register for Self Assessment
• 31st January 2026 - Deadline to file your online tax return and pay tax for the previous year and first payment on account due.

What’s a payment on account?

If your tax bill is over £1,000, HMRC will ask you to make advance payments on next year’s tax. These are due in two instalments: 31st January and 31st July. Each is usually half of your previous year’s tax bill. It’s always a bit of a surprise the first time around so plan it into your finances so you have enough to cover it.

Should you go limited?

As your business grows, there may come a point where operating as a limited company becomes more tax efficient. Limited companies pay Corporation Tax on their profits (currently 19% to 25%, depending on your annual profit), and you can pay yourself through a mix of salary and dividends, which may reduce your personal tax liability.

There are other perks too:

• You get limited liability protection
• Your credibility with clients can improve
• It can be easier to raise finance

But it also comes with extra responsibilities – filing annual accounts, running payroll and taking on more complex admin. For more information on the main considerations, we’ve put together this guide sole traders vs limited companies.

If you're considering the move, Zempler Bank can help you open a business account and even assist with your company formation, taking the hassle out of the transition.

Learn more about how to register your company with Zempler Bank.

Staying organised with your finances

Good tax habits start with good financial habits. That means:

• Keeping accurate records
• Using accounting software or a bookkeeper
• Separating personal and business finances.

Opening a dedicated business bank account makes life easier – and cleaner come tax time. It gives you a clearer view of what’s coming in and going out, which makes it easier to track expenses and plan for tax contributions.

We built the Zempler Bank business account with small businesses in mind. It gives you the tools to manage money and meet your tax obligations without the stress.

Tax is a non-negotiable

Tax might not be the most exciting part of being self-employed, but getting it right is a non-negotiable. With the right knowledge – and right systems – it becomes part of your business rhythm, not a last-minute panic.

Please note, the content in this article is not guidance from Zempler Bank and was created in whole or in part using GenAI. It may contain errors or inaccuracies and should not be relied upon as a substitute for professional advice. Zempler Bank makes no representations or warranties of any kind, explicit or implied with respect to the contents of this article. Without limitation, Zempler Bank specifically excludes and disclaims all express or implied warranties and conditions to the extent permitted by law, and any action taken using such content is strictly at the user’s risk.