From registering for Corporation Tax to understanding what your first annual accounts actually mean: a plain-English guide for new UK Ltd company directors.
Congratulations. You’ve incorporated your company. Somewhere between building the product and chasing your first customers, a quiet clock started ticking: your first year of accounts. For most founders this is unfamiliar territory, and the language doesn’t help. This guide walks through what actually happens in your first year as a UK limited company director, in plain English.
You now have two separate sets of obligations
The single most common source of confusion is that a limited company answers to two different organisations, with two different deadlines:
- Companies House: wants your statutory annual accounts.
- HMRC: wants your Company Tax Return (the CT600) and any corporation tax you owe.
These are related but separate filings. Mixing them up is where a lot of first-year stress comes from. Keeping clean records from day one is what makes both straightforward, and that is exactly what good bookkeeping is for.
Your first accounting period is probably not 12 months
When you incorporate, Companies House sets your accounting reference date to the last day of the month you registered in, one year later. But your first set of accounts usually covers a slightly longer period: from your incorporation date to that reference date, which can be up to around 18 months.
To make it more interesting, your first corporation tax period can only be a maximum of 12 months. That means your first long accounting period sometimes has to be split into two CT600 returns. It sounds fiddly because it is, and it’s one of the first things we sort out for new clients so it never becomes a problem.
The key first-year deadlines
Here’s the shape of it for a typical company:
- Register for Corporation Tax: within three months of starting to trade (HMRC counts “trading” broadly: buying, selling, advertising, employing).
- Confirmation statement: due to Companies House annually; it confirms your company details are correct. It’s separate from your accounts.
- First annual accounts to Companies House: generally due 21 months after your incorporation date.
- First Company Tax Return and payment to HMRC: corporation tax is normally due nine months and one day after the end of your accounting period; the CT600 itself is due within 12 months.
Miss a Companies House accounts deadline and the penalties start at £150 and climb. Miss HMRC’s and you’re into automatic penalties plus interest. None of this is hard to avoid. It just needs tracking, which is part of what an accountant does for you.
What your annual accounts actually contain
For most small startups, your statutory accounts (often filed as “micro-entity” or “small company” accounts) will include:
- A balance sheet: what the company owns and owes at year end.
- Supporting notes.
- For your own use (not always filed), a profit and loss account showing income, costs, and profit.
The version that goes on the public record at Companies House is usually abbreviated, so you’re not exposing detailed financials to the world. But the full picture is what tells you how your business is really doing. That is where management accounts earn their keep throughout the year, rather than waiting for an annual snapshot that’s already out of date.
”Profit” is not the same as “money in the bank”
A hard lesson for many first-year founders: your accounts can show a profit while your bank account feels empty, or vice versa. Accounts are prepared on an accruals basis: they record income when it’s earned and costs when they’re incurred, not when cash actually moves. Corporation tax is charged on accounting profit, not on your bank balance.
This is exactly why founders get caught out by their first tax bill. The cash went on growth; the tax is still due. Planning for it (ideally setting money aside monthly) is one of the most valuable habits you can build early.
Directors have personal filing duties too
If you take money out of the company as salary, dividends, or both, you may need to file a Self Assessment tax return personally. How you pay yourself (the salary versus dividends question) has a real impact on your overall tax, and it’s worth getting right from the start rather than fixing later.
What to get right in year one
If you do nothing else, do these:
- Keep your bookkeeping current. Don’t leave a year of receipts for a panicked weekend. Clean monthly records make everything downstream cheaper and more accurate.
- Separate business and personal money. A dedicated business bank account from day one saves enormous untangling later.
- Register for Corporation Tax on time. Within three months of trading.
- Set tax aside as you go. Treat corporation tax as money that was never yours to spend.
- Get advice before you need it. The cheapest time to fix a structural mistake is before it’s made.
The bottom line
Your first year of accounts feels intimidating because the system speaks its own language and runs on deadlines you didn’t set. None of it is beyond you, but most founders would rather spend that energy on the business. That’s the whole point of having a financial partner for your startup: we handle the filings, the deadlines, and the jargon, and translate your numbers back into decisions you can actually act on.
If you’ve recently incorporated and want to start on solid ground, book a free 30-minute call. We’ll tell you exactly what your first year looks like and what you need to do next.