- Company number
- 16470686
- Incorporated
- 23 May 20251 year trading
- Registered office
- Eagle House, 163 City Road, London, EC1V 1NR
- Nature of business
- Construction of commercial buildings
Build 121 Ltd is a 1-year-old private limited company registered in London, company number 16470686, one of 12,075 building contractors in London. Its next accounts are due at Companies House on 23 February 2027, and its first CT600 is due at HMRC on 22 May 2027.
Key dates
This company has not filed accounts yet. First accounts are due 21 months after incorporation, and the first period can run longer than a year.
Is this your company?
File the first accounts to Companies House and the CT600 to HMRC yourself with A.X.E.L Filing. One set of questions, both filings, £49 flat. No accountant, no subscription.
File for Build 121 LtdOr get a reminder before each deadline
Free. We email you 60, 30, 14, 7 and 1 days before the accounts, CT600 and confirmation statement are due. Unsubscribe in one click.
Where Build 121 Ltd is registered
The registered office is in London (EC1V), in the Hackney local authority area, London. Show EC1V 1NR on a map.
Other trade companies in EC1V
- Cardiff Electrical Solutions LtdElectricians
- Edemis Construction LtdBuilders
- Zaylan LtdProperty developers
- Pronto Roofing and Construction LtdRoofers
- Instal Systems LtdPlumbers and heating engineers
- J&R Partners LtdBuilders
- The Tile Craft LtdFinishing trades
- Cathal Od Solutions LtdSpecialist contractors
Also registered at this address
4 other companies use the same registered office as Build 121 Ltd.
- Bincloud Construction LtdProperty developers
- Commercial Gas Safety Certificates LtdPlumbers and heating engineers
- Design 121 LimitedSpecialist contractors
- H1 Clean LtdCleaning companies
What happens if Build 121 Ltd files late
Companies House charges an automatic penalty the day after the deadline, and it rises the longer the accounts are late. These are the dates for this company's accounts due on 23 February 2027.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 24 Feb 2027 to 23 Mar 2027 | £150 |
| 1 to 3 months late | 24 Mar 2027 to 23 May 2027 | £375 |
| 3 to 6 months late | 24 May 2027 to 23 Aug 2027 | £750 |
| More than 6 months late | From 24 Aug 2027 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Jun 2027 | £200 |
| 3 months late | 31 Aug 2027 | another £200 |
| 6 months late | 30 Nov 2027 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 May 2028 | another 10% of any unpaid tax |
For returns filed on or after 1 April 2026. Late three times in a row and the £200 penalties become £1,000 each.
Company details
As held on the Companies House register.
- Company number
- 16470686
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 23 May 2025 (1 year ago)
- Registered office
- Eagle House, 163 City Road, London, EC1V 1NR
- Nature of business
- Construction of commercial buildings (SIC 41201)
- Year end
- 31 May (accounting reference date)
- Accounts type
- No accounts filed yet
- Last confirmation statement
- 22 May 2026
Filing notes for building contractors
Building companies often run the Construction Industry Scheme as a contractor, a subcontractor or both. CIS deductions suffered during the year are set against the PAYE bill, and any unrecovered balance at the year end matters when the accounts are drawn up.
Similar companies in London
Other active building contractors registered in London.
- Build 33 Ltd2022
- Build A Property Ltd2025
- Build and Clean Solutions Ltd2024
- Build and Create Construction Ltd2013
- Build and Form Limited2022
- Build and Form Studios Ltd2026
- Build and Install Ltd2026
- Build and Manage Ltd2024
All building contractors in London · All trades in London · Builders across the UK
Frequently asked questions
When are Build 121 Ltd's accounts due?
Build 121 Ltd's next accounts are due at Companies House by 23 February 2027 (in 134 days), covering the period to 31 May 2026.
When is Build 121 Ltd's CT600 due?
The first accounts cover more than 12 months, so there are two Company Tax Returns: one for the 12 months to 22 May 2026, due by 22 May 2027, and one for the period to 31 May 2026, due by 31 May 2027. Corporation tax is payable 9 months and 1 day after the end of each.
Is Build 121 Ltd still trading?
Build 121 Ltd is listed as active on the Companies House register as of 1 Oct 2026. Active means it has not been dissolved or entered insolvency; it does not show whether it is currently taking on work.
What does Build 121 Ltd do?
Build 121 Ltd is registered under Construction of commercial buildings (SIC 41201).
How old is Build 121 Ltd?
Build 121 Ltd was incorporated on 23 May 2025, 1 year ago.
What is the penalty if Build 121 Ltd files its accounts late?
Companies House charges £150 if the accounts are up to 1 month late, £375 up to 3 months, £750 up to 6 months and £1,500 after that, doubled if the previous year's accounts were also late. HMRC charges £200 for a CT600 filed a day late and another £200 at 3 months.
Official records
View Build 121 Ltd on Companies House for filed documents, officers and the full history.
Based on the Companies House register (snapshot 1 Oct 2026). Deadlines are worked out from the register and assume a standard accounting period; a change of year end or a short period moves them. This page is general information, not tax or accountancy advice.