Top SIC codes by new UK company registrations, H1 2026

400,176 companies were incorporated in the UK in the first half of 2026 — down 5.9% on the first half of 2025, when 425,088 were registered. The single most-registered activity was Retail via mail order or internet (SIC 47910) with 35,294 new companies, 8.82% of every company formed in the period.

This report measures the whole period exactly, code by code, from the Companies House register. It covers what was registered, what grew and shrank against H1 2025, how formations moved month by month, and which segments are worth acting on. Methodology and the full dataset are at the end.

Key findings

• 400,176 incorporations in H1 2026, down 5.9% year on year (425,088 in H1 2025).
• Retail via mail order or internet (47910) was the most-registered activity, with 35,294 new companies — ahead of Letting of own real estate (68209) on 32,484.
• The top three codes together account for 23.1% of all registrations (companies may list more than one code, so this is a share of companies, not a partition).
• Software development (SIC 62012) grew fastest among codes of meaningful size, +71.4% to 20,765 registrations.
• Retail trade (SIC 47990) fell hardest, −28.0% to 5,868.
• Mar was the busiest month with 74,137 incorporations; Feb was the quietest at 60,477.

The most-registered SIC codes in H1 2026

Of the ten largest codes, 3 sit in technology, 2 sit in real estate, 1 sits in retail & wholesale, and the remainder are spread across 4 further sectors. A caveat that matters when reading any SIC ranking: a company may register up to four SIC codes, so a single company can appear under several rows here. The shares are shares of companies incorporated, not slices of a pie, and they do not sum to 100%.

It is also worth being precise about what a registration is. These are companies added to the register — not businesses that have started trading, hired anyone or invoiced a customer. Company formation agents register companies in volume, and some codes (particularly holding and property vehicles) reflect structuring rather than new economic activity.

What changed against H1 2025

Percentage changes are only reported for codes registering at least 400 companies in H1 2026. Below that, a swing of tens of companies produces a dramatic-looking percentage that says nothing about the underlying market.

Formation is only half the picture

A code with high registrations and equally high dissolutions is churning, not growing. The table below sets new registrations against companies dissolved in the same window — note that dissolutions cover companies of any age, not just those formed in H1 2026, so this is a measure of net register movement rather than a survival rate.

How formations moved through the period

Monthly formation volume is strongly seasonal and sensitive to working days, bank holidays and the tax year. Read the shape, not any single month.

How to act on this data

Rankings are only useful if you can reach the companies behind them. Each segment below links to the live list of companies on that code — the register updated daily, not a snapshot of this report.

The commercial reading, sector by sector, is straightforward:

• Retail via mail order or internet. Online retailers commit to a payment processor and a fulfilment partner almost immediately after incorporating.
• Letting of own real estate. A newly registered property vehicle usually precedes a purchase or refinance, so the buying window is short and dated.
• Management consultancy. New consultancies need professional indemnity cover and a compliant billing setup before they can invoice a first client.
• Software development. New tech companies pick their accountant, payroll and cloud stack in the first 90 days and rarely revisit the decision.

If you want these companies as they appear rather than in a half-yearly report, free new-company alerts send new registrations matching your criteria each week, and company monitoring tracks changes on companies you already care about.

Methodology

Where the figures come from. Every figure is an exact hit count from the Companies House advanced company search API, filtered on incorporation date (and SIC code, where stated). Counts were taken on 2026-10-08 and cover companies incorporated between 2026-01-01 and 2026-06-30 inclusive, irrespective of whether those companies are still active today.

How the codes were chosen. There is no register endpoint that ranks SIC codes, so candidate codes were identified from a stratified sample of 6,000 companies incorporated in the period (one page per month), unioned with the 62 codes CompaniesIQ maintains reference pages for. That produced 180 candidate codes, each of which was then counted exactly. Sampling only decides which codes to measure; no published figure is estimated from it.

Reproducing this. Each row can be checked directly against the register. A single query — the advanced search endpoint with sic_codes, incorporated_from and incorporated_to set — returns the same hit count reported here, subject to later register revisions. The full query ledger for this edition is available in the dataset download.

Limitations.

• A company may register up to four SIC codes. Companies are therefore counted under each code they list, and the shares below do not sum to 100%.
• These are registrations, not trading businesses. A registered company may never trade, and formation agents register companies in bulk.
• Counts move slightly over time as late registrations and corrections are processed by Companies House.

Data and licence

• Period covered: 2026-01-01 to 2026-06-30 (inclusive).
• Source: Companies House register (advanced company search API).
• Retrieved: 2026-10-08.
• Licence: Contains public sector information licensed under the Open Government Licence v3.0. Company data © Crown copyright.
• Download: top-sic-codes-uk-company-registrations-h1-2026.csv — every measured code, both periods, and the query behind each figure.

Citation. CompaniesIQ Research (2026). Top SIC codes by new UK company registrations, H1 2026. Available at: https://www.companiesiq.co.uk/blog/top-sic-codes-uk-company-registrations-h1-2026

You are welcome to reuse these figures and charts with attribution and a link to this page.