- Company number
- 16313562
- Incorporated
- 13 Mar 20251 year trading
- Registered office
- Unit A4 Mardy Trading Estate, Gorseinon, Swansea, SA4 4HJ
- Nature of business
- Glazing
Thermaplas Ltd is a 1-year-old private limited company registered in Swansea, company number 16313562, one of 17 glazing companies in Swansea. Its next accounts are due at Companies House on 13 December 2026, and its first CT600 is due at HMRC on 12 March 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 Thermaplas 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 Thermaplas Ltd is registered
The registered office is in Swansea (SA4), in the Swansea local authority area, Wales. Show SA4 4HJ on a map.
Other trade companies in SA4
- Prometheus Scaffolding LimitedScaffolders
- Ridgewood Property Group LtdBuilders
- Trident Infrastructure Projects LtdCivil engineering
- Top Tint Vehicles Commercial & Domestic LimitedMechanics and garages
- RHV Solutions LimitedElectricians
- Bay Divers Services LtdMachinery repair and installation
- Dmo Automotive Services LtdMechanics and garages
- Biggs Contracting Services LtdBuilders
What happens if Thermaplas 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 13 December 2026.
| Companies House | Accounts delivered | Penalty |
|---|---|---|
| Up to 1 month late | 14 Dec 2026 to 13 Jan 2027 | £150 |
| 1 to 3 months late | 14 Jan 2027 to 13 Mar 2027 | £375 |
| 3 to 6 months late | 14 Mar 2027 to 13 Jun 2027 | £750 |
| More than 6 months late | From 14 Jun 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
- 16313562
- Status
- Active
- Company type
- Private limited company
- Incorporated
- 13 March 2025 (1 year ago)
- Registered office
- Unit A4 Mardy Trading Estate, Gorseinon, Swansea, SA4 4HJ
- Nature of business
- Glazing (SIC 43342)
- Year end
- 31 March (accounting reference date)
- Accounts type
- No accounts filed yet
- Last confirmation statement
- 12 March 2026
Filing notes for glazing companies
Glazing companies often take deposits before work starts. Deposits held at the year end are a liability, not income, until the job is done.
Similar companies in Swansea
Other active glazing companies registered in Swansea.
- Trade Cost Windows Limited2012
- A Rated Home Improvements Limited2010
- Alan Hancock Aluminium Doors & Windows Limited2009
- Aspect Aluminium Limited2017
- Coastline Windows Limited2025
- Cymru Guardian Windows Limited2025
- Express Windows (South Wales) Ltd2023
- Glasshorizon Designs Ltd2023
All glazing companies in Swansea · All trades in Swansea · Glaziers across the UK
Frequently asked questions
When are Thermaplas Ltd's accounts due?
Thermaplas Ltd's next accounts are due at Companies House by 13 December 2026 (in 61 days), covering the period to 31 March 2026.
When is Thermaplas 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 12 March 2026, due by 12 March 2027, and one for the period to 31 March 2026, due by 31 March 2027. Corporation tax is payable 9 months and 1 day after the end of each.
Is Thermaplas Ltd still trading?
Thermaplas 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 Thermaplas Ltd do?
Thermaplas Ltd is registered under Glazing (SIC 43342).
How old is Thermaplas Ltd?
Thermaplas Ltd was incorporated on 13 March 2025, 1 year ago.
What is the penalty if Thermaplas 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 Thermaplas 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.