- Companies
- Civil engineering
- Northampton
- Semilong Services Limited
Semilong Services Limited
- Company number
- 06842550
- Incorporated
- 10 Mar 200917 years trading
- Registered office
- 15 Gate Lodge Close, Round Spinney Industrial Estate, Northampton, NN3 8RJ
- Nature of business
- Construction of water projects
Semilong Services Limited is a 17-year-old private limited company registered in Northampton, company number 06842550, one of 152 civil engineering contractors in Northampton. Its next accounts are due at Companies House on 31 December 2026, and the CT600 for the period to 31 March 2026 is due at HMRC on 31 March 2027.
Key dates
Worked out from the year end and filing history on the Companies House register.
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Finances
From each year's balance sheet filed at Companies House. Small companies do not have to publish turnover or profit, so these are balance sheet figures.
- Net assets up £217K (+17.1%) on the year before, to £1.5M.
- Net assets rose in 7 of 9 year-on-year comparisons on record.
- Current assets of £1.5M against £521K owed within a year: 2.8 times cover.
- 13 employees on average during the year.
- Balance sheets on record for 10 years, 2016 to 2025.
Net assets by year
| Year end | Net assets | Cash | Current assets | Owed within a year | Employees |
|---|---|---|---|---|---|
| 31 Mar 2025 | £1.5M | £312K | £1.5M | £521K | 13 |
| 31 Mar 2024 | £1.3M | £125K | £1.5M | £792K | 13 |
| 31 Mar 2023 | £685K | £28K | £843K | £543K | 5 |
| 31 Mar 2022 | £574K | £4,953 | £720K | £592K | 5 |
| 31 Mar 2021 | £458K | £110K | £582K | £555K | 5 |
| 31 Mar 2020 | £388K | £17K | £364K | £402K | 4 |
| 31 Mar 2019 | £296K | £679 | £221K | £279K | |
| 31 Mar 2018 | £201K | £44K | £156K | ||
| 31 Mar 2017 | £256K | £108K | £181K | ||
| 31 Mar 2016 | £351K | £28K | £237K | £198K |
Public contracts won
Semilong Services Limited has 25 public sector contract awards on record; the ones with their own published value total £11M, from 2020 to 2026. Source: Contracts Finder and Find a Tender award notices. For 6 of them the published figure is a shared or multi-year ceiling (a framework place, a multi-supplier award, or more than a small company could hold alone), so no value is shown. 7 of these were matched by the company's exact name because the notice gave no company number.
Awards by year
Main buyers
- West Northamptonshire Council12 awards
- Greensquareaccord Limited1 award
- Nottingham City Council1 award
- Nuneaton and Bedworth Borough Council1 award
- Platform Housing Limited1 award
| Buyer | Contract | Value | Awarded |
|---|---|---|---|
| Greensquareaccord Limited | Hooks Close | £120K | 7 Oct 2026 |
| Nottingham City Council | CPU 7468 Highways Gully Cleaning & Road Sweeping Framework | Ceiling, not shown | 1 Jul 2026 |
| West Northamptonshire Council | Refurbishment Works to County Hall | £49K | 1 Jun 2026 |
| West Northamptonshire Council | Moulton Primary School - New Entrance Extension | £199K | 22 May 2026 |
| Nuneaton and Bedworth Borough Council | NUN - Drainage Maintenance 26/29 | £1.3M | 5 May 2026 |
| Platform Housing Limited | Roman Close - Remediation Works | £770K | 16 Apr 2026 |
| West Northamptonshire Council | Delapre Annexe - Roof Replacement/Repairs and Refurbishment | £283K | 1 Apr 2026 |
| North Northamptonshire Council | North Northamptonshire Council Refurbishment of Phoenix House | £45K | 27 Feb 2026 |
| Platform Housing Group | Roman Close - Remedial Works | £770K | 27 Feb 2026 |
| Midland Heart Limited | Roofing Planned Installation and Responsive Repairs | Ceiling, not shown | 25 Feb 2026 |
Showing the 10 most recent of 25.
Where Semilong Services Limited is registered
The registered office is in Northampton (NN3), in the West Northamptonshire local authority area, East Midlands. Show NN3 8RJ on a map.
Other trade companies in NN3
- Building Services LtdBuilders
- Cma Constuction Group LtdSpecialist contractors
- Auto Correct Repairs LtdMotor traders
- LCK & Son LimitedLandscapers and gardeners
- Atlas Engeenering LtdCivil engineering
- Oakwell Energy Systems LtdElectricians
- Imdl Construction LtdBuilders
- BC Developments and Construction Group UK LtdProperty developers
What happens if Semilong Services Limited 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 31 December 2026.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 1 Jan 2027 to 31 Jan 2027 | £150 |
| 1 to 3 months late | 1 Feb 2027 to 31 Mar 2027 | £375 |
| 3 to 6 months late | 1 Apr 2027 to 30 Jun 2027 | £750 |
| More than 6 months late | From 1 Jul 2027 | £1,500 |
Penalties double if the accounts were also late the year before.
| HMRC (CT600) | From | Penalty |
|---|---|---|
| 1 day late | 1 Apr 2027 | £200 |
| 3 months late | 30 Jun 2027 | another £200 |
| 6 months late | 30 Sep 2027 | HMRC estimates the tax and adds 10% of the unpaid tax |
| 12 months late | 31 Mar 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
- 06842550
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 10 March 2009 (17 years ago)
- Registered office
- 15 Gate Lodge Close, Round Spinney Industrial Estate, Northampton, NN3 8RJ
- Nature of business
- Construction of water projects (SIC 42910)
- Year end
- 31 March (accounting reference date)
- Accounts type
- Unaudited abridged
- Last accounts made up to
- 31 March 2025
- Last confirmation statement
- 10 March 2026
Filing notes for civil engineering contractors
Civil engineering contractors usually carry plant and machinery, so capital allowances (the annual investment allowance and the main pool) do much of the work in the corporation tax computation.
Similar companies in Northampton
Other active civil engineering contractors registered in Northampton.
- SF Management & Maintenance Ltd2021
- Shortland Construction Limited2004
- Signature Surfaces Northants Ltd2026
- Simo Groupwork Ltd2025
- Simply Commspace Limited2025
- SM Project Management Services Ltd2017
- SMH Civils Limited2021
- Sofrozyne Ltd2025
All civil engineering contractors in Northampton · All trades in Northampton · Civil engineering across the UK
Frequently asked questions
When are Semilong Services Limited's accounts due?
Semilong Services Limited's next accounts are due at Companies House by 31 December 2026 (in 79 days), covering the period to 31 March 2026.
When is Semilong Services Limited's CT600 due?
The CT600 for the period to 31 March 2026 is due at HMRC by 31 March 2027, 12 months after the period end. The corporation tax itself is payable earlier, by 1 January 2027.
Is Semilong Services Limited still trading?
Semilong Services Limited 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 Semilong Services Limited do?
Semilong Services Limited is registered under Construction of water projects (SIC 42910).
How old is Semilong Services Limited?
Semilong Services Limited was incorporated on 10 March 2009, 17 years ago.
Has Semilong Services Limited won public sector contracts?
Yes. Semilong Services Limited has 25 contract awards from public bodies on Contracts Finder and Find a Tender (those with their own published value total £11M), most recently from GREENSQUAREACCORD LIMITED.
What is the penalty if Semilong Services Limited 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 Semilong Services Limited 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.