Seccl says it now powers more than one million investors

Seccl, the UK investment-infrastructure firm owned by Octopus Group, said on 24 September 2026 that more than one million investors now rely on its software and services. The company said this figure had doubled in less than 12 months.

The number does not describe one million people with a direct customer relationship with Seccl. Seccl is a business-to-business technology and custody provider: it sits behind investment features that banks, fintechs, advisers and consumer brands sell under their own names. The "investors" Seccl counts are the end users of those partner-branded propositions, wherever Seccl provides the dealing, custody or administration underneath. That distinction matters for a UK reader, because it means most of the million will never see the Seccl name.

It matters now because Seccl's client list has grown to include some of the best-known names in UK retail finance. Monzo migrated its existing investment proposition onto Seccl's infrastructure in the year to September 2026. Tide launched a dedicated business investment account built on Seccl in June 2026. MoneySuperMarket added an in-app investment service powered by Seccl the following month. Together, these mandates suggest that outsourced investment infrastructure is becoming a more contested part of UK fintech, though the packet available for this article does not include current independent data on how the supplier market is now structured.

What the milestone actually measures

All of the growth figures in this article are Seccl's own, drawn from its announcements and website, and none of them has been independently audited in the material reviewed for this piece.

Seccl's published snapshots show the following:

The direction of travel is clear. The precise claim that the base "doubled in less than 12 months" is harder to verify: Seccl's milestone announcement does not state the exact comparison date or the exact starting count it is measuring from, so the figure cannot be reconstructed precisely from the company's other published snapshots. The broad scale of growth across 2025 and 2026 is well evidenced; the specific doubling claim should be read as Seccl's own characterisation.

Seccl also said it processed more than 50 million transactions between 1 January and 24 September 2026, which it calculated as roughly 660,000 transactions per member of its operations team, and that more than 25,000 transfers were being initiated each month to Seccl-powered platforms as of 24 September 2026. Seccl did not disclose how it defines a transaction, its operations headcount, or what proportion of "initiated" transfers go on to complete. It also said assets under administration and revenue were each split roughly evenly between advised platforms and direct-to-consumer platforms, without publishing the underlying monetary totals.

Seccl further compared its one million investors with the Financial Conduct Authority's (FCA) estimate that 19.0 million UK adults, or 35% of adults, held investments in 2024, once people whose only holdings were property or other real assets are excluded. That FCA figure comes from the Financial Lives 2024 survey, fielded between 5 February and 16 June 2024 among 17,950 respondents, and was cited in FCA consultation paper CP25/17. Dividing Seccl's count by the FCA figure gives roughly 5.3%, or about one in 20. This is Seccl's own arithmetic, not an FCA assessment of market share: it sets a September 2026 company count against a population estimate drawn from 2024 fieldwork, and it should not be read as an official measure of Seccl's position in the UK investment market.

How Monzo added scale

Monzo's migration may be an important contributor to that growth, though its scale cannot be quantified from the information Seccl and Monzo have published. Seccl announced in July 2025 that it would migrate Monzo's existing investment and pension product onto its platform, and said at the time that more than 300,000 existing Monzo investment or pension customers had been notified about the change. Monzo's current customer-facing documentation confirms that Seccl Custody Limited is now its investment-services partner, handling dealing, custody and Stocks and Shares ISA administration. Monzo's own public material does not independently state how many customers were actually migrated, so the 300,000-plus figure rests on Seccl's disclosure rather than on Monzo confirmation.

Embedded investing beyond banking

Tide and MoneySuperMarket show Seccl's infrastructure being applied outside a banking app. Tide launched a dedicated business investment account for its small and medium-sized enterprise customers on 30 June 2026. Seccl provides the infrastructure and custody, P1 Investment Services Limited supplies the regulated platform arrangement, and Vanguard supplies the initial funds. MoneySuperMarket, a consumer comparison site, launched an in-app investment service in July 2026; its help centre states that Seccl powers the platform and acts as custodian.

The pattern across all three is the same: a recognised UK consumer or business brand sits at the front end, while Seccl and its regulated partners handle the custody, dealing and administration that a customer rarely sees.

What this says about competition

The UK's market for outsourced retail investment-platform technology has historically been concentrated. In November 2020, the Competition and Markets Authority (CMA) blocked FNZ's proposed acquisition of GBST, finding that FNZ and GBST were leading suppliers of UK retail-platform technology facing few other significant rivals. At that time, the CMA's assessment treated Seccl as a recent entrant that was not operating at comparable scale to the two larger firms.

Seccl's ability, six years on, to win mandates from Monzo, Tide and MoneySuperMarket indicates that it has extended its reach across banking, SME finance and consumer comparison services under its own brand-agnostic model. That is a meaningful signal of competitive activity in a market the CMA once described as narrow. It is not, on its own, evidence of Seccl's current market share, pricing position, or performance relative to FNZ, GBST, Hubwise or any other infrastructure provider. No current independent market-share study for 2026 was available for this article, so any comparison between Seccl and its rivals today should be treated as unresolved rather than settled.

Regulation, custody and risk

Seccl Custody Limited is authorised and regulated by the FCA under firm reference number 793200. That authorisation covers Seccl's custody-related investment services; it does not mean the FCA endorses the products sold by Monzo, Tide, MoneySuperMarket or any other partner brand, and it does not remove the ordinary risks of investing. Readers can check a firm's current permissions directly on the FCA Financial Services Register before relying on any partner proposition.

Whatever the front-end brand, money placed into an investment account built on this kind of infrastructure can fall in value as well as rise, and a customer could get back less than they put in. Custody arrangements and FCA authorisation do not protect an investor from ordinary market losses, and they do not amount to a guarantee of returns.

What to watch next

Several questions in this story remain open. Seccl has not published a methodology explaining how it defines an "investor" or whether the count strips out duplicate, dormant or closed accounts. It has not disclosed current assets under administration or revenue in absolute terms, only an approximate 50:50 split between advised and direct-to-consumer business. No completion data has been published for the 25,000-plus transfers Seccl says are initiated each month, so it is not clear what share of those actually complete. And no current, independent assessment of UK platform-technology market shares was identified to test whether the competitive hierarchy the CMA described in 2020 still holds. Further disclosure from Seccl, from its partner brands, or from an independent market study would help settle each of these points.