Closing down & dormancy
A newly incorporated company must file first accounts within 21 months of incorporation, and CT600 within 12 months of the period end.
Written and reviewed by Waqas Sagar Member of ICAEW, Fellow of ACCA, Fellow of AAT, a double graduate and entrepreneur at heart, helping startups grow and serving thousands of businesses nationwide with an excellent team. Published by LimitedCompany.Accountants, 12 London Road, Morden, London SM4 5BQ. Reviewed 12 September 2026 against 2026/27 UK rates and current Companies House and HMRC guidance.
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QuickBooks PartnerCertified ProAdvisor100+ yearsCombined team experienceFully insuredUp to £2m indemnityYes, in practice. Your first accounting reference date is usually 12 months after incorporation, first accounts are due 21 months after incorporation, and the first corporation tax return is due 12 months after the accounting period ends. An accountant sets these up correctly from day one.
Why the first period is different
What an accountant sets up
Common early pitfalls
Yes, in practice. Your first accounting reference date is usually 12 months after incorporation, first accounts are due 21 months after incorporation, and the first corporation tax return is due 12 months after the accounting period ends. An accountant sets these up correctly from day one.
Companies House sets an accounting reference date automatically at the last day of the month in which incorporation falls, one year on. The first accounts filing deadline is unusually generous at 21 months from incorporation rather than the normal nine months, but only for that first period.
The first accounting period for corporation tax purposes cannot exceed 12 months, so if your Companies House year is longer than that, HMRC requires two CT600 returns covering the split. Getting this wrong is one of the most common early mistakes for new directors filing themselves.
Registration for corporation tax within three months of starting to trade, a bookkeeping system from the first transaction, and a decision on whether to shorten or extend the first accounting reference date to align with a sensible year end for the business.
Fixed monthly packages start at £89 plus VAT and include first year accounts and the CT600 as part of the ongoing service, so the cost is known from the outset rather than being a separate one-off bill.
Directors often assume the 21 month deadline applies every year; it only applies to the first set of accounts. Missing the switch to the normal nine month deadline in year two is a frequent and avoidable penalty trigger.
Late registration for corporation tax, or registering for VAT or PAYE only when a threshold is breached rather than in advance, also causes avoidable admin. An accountant flags these dates against your specific incorporation date rather than a generic calendar.
Rates, thresholds and deadlines quoted here reflect the 2026/27 UK position and current Companies House and HMRC guidance. Check GOV.UK, or ask us, before relying on them for your own company.
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We work with company directors across London and Surrey from our office at 12 London Road, Morden, London SM4 5BQ. Pick your area, or send the form below and we will call you back.
Frequently asked
Within 14 days of the review period ending, which is 12 months after incorporation, then annually from there.
Yes, before the filing deadline for that period, subject to Companies House rules on shortening or extending.
Only once you start trading, but within three months of that date, not from incorporation itself.
Keep bank statements, sales and platform reports, purchase invoices, payroll records, VAT workings, finance agreements and Companies House correspondence. We confirm the exact list at onboarding and identify gaps before a filing deadline becomes urgent.
The fee depends on transaction volume, record quality, VAT and payroll requirements, historic catch-up and the level of reporting needed. We agree a fixed scope and price before technical work starts, with published packages available on our fees page.
Yes. We request professional clearance, collect the prior records and authorities, check the next Companies House and HMRC deadlines, and give you one clear handover list. The process is normally completed remotely.
Yes. We work through secure cloud records, scheduled reviews and digital approvals, while keeping a named team available by phone, video call and email. Clients can also visit our Morden office by appointment.
We regularly work with Xero, QuickBooks, FreeAgent, Sage and connected sales or expense apps. The right setup depends on transaction volume, integrations and the reports you need, not simply the software brand.
The relevant calendar may include annual accounts, Corporation Tax payment and return dates, confirmation statements, VAT returns, payroll submissions and Self Assessment. We map the dates from your company year end and registrations.
No. This page explains general UK rules and common accounting treatment. Your facts, contracts and wider tax position must be reviewed before you rely on a conclusion.
Included approach
Check the current rules
Deadlines, thresholds and filing rules change. GOV.UK and Companies House publish the current statutory position; advice should then be applied to your company’s circumstances.
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Pick a time that suits you and a qualified accountant will call you about your company, deadlines and fees.
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