Active14830471Private limited companyLondon

PROTONERA LTD

D39/100

Owned by Chengzhi Guo and Professor Erwin Reisner

Summary

Generated from filed data · no estimates

PROTONERA LTD is an active private limited company (company number 14830471) incorporated on 26 April 2023, registered in London. Its registered activity is other research and experimental development on natural sciences and engineering (SIC 72190). Latest small accounts cover the period ending 30 April 2025, showing net assets of −£33k and cash of £38k, with 2 employees on average. Net assets rose 8% on the prior period (−£37k).

Peer position · net assets

By net assets it sits in the bottom quarter of 654 comparable companies in London (median £101, upper quartile £41k).

Key dates

Incorporated: 26 April 20233 yrs ago
Next accounts due: 30 January 2027in 100 days
Confirmation statement due: 10 May 2027in 200 days

Due dates are expected from Companies House filing rules; confirm on the official register before relying on them.

Activity

SIC 72190: Other research and experimental development on natural sciences and engineering
Accounts type: Total Exemption Full
Size band: MicroCompanies Act thresholds

Financials

2 periods on record · latest ending 30 April 2025

Net assets

−£33k

vs Apr 2024

Cash at bank

£38k

−20%vs Apr 2024

Turnover

Not reported

Employees

−33%vs Apr 2024

Net assets

−£33k

Cash at bank

£38k

Average employees

Filed accounts by period, newest first
Period end	Net assets	Cash	Debtors	Creditors <1y	Turnover	Profit	Employees
30 April 2025	−£33k	£38k	£19k	—	—	—	2
30 April 2024	−£37k	£48k	£15k	—	—	—	3

Cash per employee£19kCash ÷ average employees

Figures as filed in iXBRL accounts at Companies House. "—" means the line was not reported in that filing.

Firmoscan score

Rules-based · every point shows its evidence

39 / 100 · grade D

Score breakdown
50	Starting scoreEvery scored company starts here
−15	Negative net assetsNet assets £-33,495 at 2025-04-30
+4	Past first filingsIncorporated 2023-04-26
39	Score, grade D

A transparent, rules-based score from filed data only: every point lists its evidence. It is not a credit rating or advice. How the score is computed.

Ownership and control

2 active · 1 other

CG
Chengzhi Guo
Individual · since 26 April 2023
- owns 25–50% of shares
- holds 25–50% of voting rights
- can appoint or remove directors
25–50%
PE
Professor Erwin Reisner
Individual · since 21 January 2024
- owns 25–50% of shares
- holds 25–50% of voting rights
25–50%
SB
Subhajit Bhattacharjee
Individual · since 26 April 2023 · ceased 21 January 2024
- owns 25–50% of shares
- holds 25–50% of voting rights
25–50%

Persons with significant control hold 25% or more of shares or voting rights. Smaller shareholdings are only listed in confirmation-statement documents.

Timeline

Newest first

10 May 2027Confirmation statement duein 200 days
30 Jan 2027Next accounts duein 100 days
30 Apr 2025Accounts period endNet liabilities £33k · small accounts
30 Apr 2024Accounts period endNet liabilities £37k · small accounts
26 Apr 2023Incorporated

Similar companies in London

Same activity (other research and experimental development on natural sciences and engineering), closest in incorporation date

All companies incorporated on 26 April 2023 · in Apr 2023.

Reminders for PROTONERA LTD

Get an email before each filing deadline — accounts and confirmation statement — so nothing is late.