Flagstone
Flagstone is a UK FCA-regulated cash deposit marketplace aggregating 450+ savings accounts from 65+ partner banks, serving HNW individuals, businesses, charities, advisers and financial partners via a unified API-enabled platform, monetising through a share of interest from bank partners.
- Company typePrivate
- Founded2013
- HeadquartersLondon, United Kingdom
- Headcount251–500
- GTM typeB2B and B2C
- OfferingServices
What Flagstone does
Flagstone is a UK-regulated cash deposit marketplace that aggregates more than 450 savings accounts from over 65 partner banks into a single consumer and enterprise platform, enabling individuals, businesses, charities, financial advisers and institutional partners to spread deposits across multiple banking groups for higher interest and FSCS protection of up to £120,000 per client per banking group. Headquartered in London (Clareville House, SW1Y 4EL) and operating since 2013, Flagstone Group Ltd is authorised and regulated by the Financial Conduct Authority under the Payment Service Regulations 2017 (FRN 605504) and registered with the ICO (ZA033774), with a wholly-owned Jersey-registered related entity, Flagstone International Limited (JOIC 71026), extending the proposition cross-border.
Underpinning the platform is a version-stable REST API suite documented to OpenAPI 3.0.1 and in production since 2019, comprising five APIs: Client API (onboarding and KYC, version 2020-08-01), Product Catalog API (browsing of savings products and FSCS status, version 2022-07-01), Instruction Request API (deposits, withdrawals, closures, version 2021-11-01), Portfolios API (positions and balances, version 2020-04-01) and Instruction Batches API (daily settlement cycle). The infrastructure supports optimistic concurrency versioning, caller-supplied GUID idempotency, sandbox and production environments, multi-currency settlement (GBP, EUR, USD), and sustained throughput of up to 50 requests per second, having processed 100M+ instructions annually and £100bn+ in cumulative capital transfers. Consumer-facing tooling includes a holding account, sample portfolio builder, interest/ISA/inheritance/compound interest calculators, and the Savings Academy content hub; an AI-powered chatbot handles client enquiries with Article 22 GDPR safeguards.
The business model is asset-light and primarily transactional: end consumers pay no admin, management or platform fees, and Flagstone instead receives a share of the interest paid by partner banks on each account opened through the platform, deducted before the headline rate is shown to the saver. A secondary revenue stream comes from API-based transactional and AUM-driven economics charged to financial partners (pension providers, wealth managers, SIPP operators and other financial institutions) that integrate via the API suite. A complementary B2B bank panel programme lets UK banks (including HSBC, Allica and OakNorth) source high-value savers and trial new products without their own API integration. The platform manages over £17bn in client cash, reported £55m in FY2024 turnover and employs over 350 staff; the latest disclosed product addition is the Flagstone Cash ISA, launched February 2026.
Flagstone firmographics
Firmographics- Name
- Flagstone
- Legal name
- Flagstone Group Ltd
- Website
- https://flagstoneim.com
- Company type
- Private
- Founded year
- 2013
- Operating status
- Operating
- Headcount range
- 251–500 employees
- Short description
- Flagstone is a UK FCA-regulated cash deposit marketplace aggregating 450+ savings accounts from 65+ partner banks, serving HNW individuals, businesses, charities, advisers and financial partners via a unified API-enabled platform, monetising through a share of interest from bank partners.
- Ownership category
- akta.pro rank
Flagstone industry classification
Industry- Product category
- Cash Deposit Platform
- NAICS
- Depository Credit Intermediation (5221)
- SIC
- Functions Related To Depository Banking, Nec (6099)
- akta.pro primary industry
- Digital Wallets & Account Aggregation Hub (Multi-account, Stored Value) (FSAGAAAD)
- akta.pro secondary industries
- Mass-Market Consumer Deposit Banking (Checking/Savings) (FSABAAAA), Treasury, Cash Management & Liquidity Tools (Sweeps, Cash Concentration) (FSAGAAAG)
Keywords
Where Flagstone is headquartered
LocationHeadquarters
- HQ city
- London
- HQ country
- United Kingdom
- HQ region
- Europe
Offices1 record
Markets served
Flagstone business model
Business model- GTM type
- B2B and B2C
- Offering type
- Services
- Cost components
- Personnel, Technology or R&D, Operations, Marketing or Sales, Infrastructure
Revenue model
- Share of interest from bank partners: For each savings account opened through Flagstone with a partner bank, Flagstone receives a small share of the interest paid by the bank. The share is deducted before the rate is displayed to the client, so the headline rate is the rate the saver receives. No admin, management or platform fees are charged to clients. This is the primary revenue stream and is transactional/commission-based on deposits routed through the platform.
- API partner revenue from financial institutions: Revenue from financial partners (pension providers, wealth managers, SIPPs, banks) that integrate via the API suite to source deposits for their clients across 60+ banks. Per-instruction and AUM-driven economics implied by API integration model.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Other | Pay-as-you-go | Free for end users — revenue via share of interest from bank partners |
| Transaction based/ take rate | Pay-as-you-go | API-based pricing for financial partners (quote-based, not publicly itemised) |
Go-to-market motion4 records
Distribution channels4 records
Marketing channels9 records
Flagstone product offering
Product offeringCore offering
Flagstone operates an FCA-authorised cash deposit platform that aggregates 450+ savings accounts from 65+ UK partner banks into a single customer interface, enabling individuals, businesses, charities and adviser-introduced clients to spread deposits for higher interest and up to £120,000 FSCS protection per banking group. The consumer platform is complemented by an enterprise REST API suite used by pension providers, wealth managers and SIPPs to access 60+ banks through one integration, plus a bank panel programme that lets UK banks distribute their savings products on Flagstone's platform. The company earns revenue via a share of the interest paid by partner banks on each account opened through the platform, with no fees charged to end users.
Product overview
Flagstone operates as a unified cash deposit platform that aggregates 450+ savings accounts from 65+ UK partner banks into a single customer interface, anchored by the core Flagstone Savings Platform and its sub-products: the Flagstone Cash ISA (multi-bank tax-free wrapper launched February 2026), Fixed Rate Savings Accounts, Notice Savings Accounts, and Instant Access Savings Accounts. Underpinning the consumer platform, Flagstone exposes five distinct REST APIs (Client API, Product Catalog API, Instruction Request API, Portfolios API, and Instruction Batches API) that enable pension providers, wealth managers, and financial institutions to embed multi-bank savings into their own propositions. The platform is complemented by the B2B Partner Banks Programme (used by HSBC, Allica, and OakNorth), the Invite a Friend referral programme, and a separate Flagstone International sub-brand.
Differentiator
Problem solved
Functional benefit
Products and services
- Flagstone Savings Platform
Quantifiable outcome
- Over £17bn in client cash managed through the platform
- +4 more outcomes
Companies that use Flagstone
Customer profileNamed customers4 records
Segments6 records
Ideal customer profiles5 records
Flagstone technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- Yes
- API docs
- API detail
Core technology
AI maturity
App detail
Integration10 records
AI capability3 records
Feature6 records
Flagstone partnerships and signals
Strategic signalPartnerships
23 partnerships are on record, tiered flagship and core.
- HSBC UKflagshipHSBC lists savings accounts on the Flagstone platform, including competitive and exclusive rates, to reach high-value savers without its own API integration. Named in the Partner Banks page as a flagship bank using Flagstone to source flows from thousands of new clients.
- SantanderflagshipSantander appears as a featured partner bank on the Flagstone homepage and lists savings products on the platform for Flagstone's high-value saver base.
- NationwideflagshipNationwide Building Society is featured as a partner bank on the Flagstone homepage and lists savings accounts on the platform.
- ShawbrookflagshipShawbrook is featured on the homepage (including as a Notice 45 Day account at 3.89% AER | 3.83% gross) and lists savings products on the Flagstone platform.
- Allica BankflagshipNamed on the Partner Banks page as a bank using Flagstone to source flows from thousands of new clients. Featured on the homepage among partner banks.
- OakNorth BankflagshipNamed on the Partner Banks page as a bank using Flagstone to source flows from thousands of new clients. Featured on the homepage among partner banks.
- AldermorecoreAldermore lists savings accounts on the Flagstone platform as part of the 65+ partner bank network.
- Principality Building SocietycorePrincipality lists savings products on the Flagstone platform and is featured among partner banks on the homepage.
- ABC (Arab Banking Corporation)coreABC lists savings products on the Flagstone platform as part of the 65+ partner bank network.
- MetrobankcoreMetrobank lists savings products on the Flagstone platform as part of the 65+ partner bank network.
- Paragon Banking GroupcoreParagon lists savings products on the Flagstone platform as part of the 65+ partner bank network.
- Standard CharteredcoreStandard Chartered lists savings products on the Flagstone platform as part of the 65+ partner bank network.
- Financial partners (pension providers, wealth managers, financial institutions)flagshipStrategic API integration partners including pension providers, SIPPs, wealth managers and financial institutions. They integrate once with Flagstone's version-stable API suite to access 60+ banks, onboard clients, submit instructions and report portfolios. APIs have powered the multi-billion-pound platform in production since 2019.
- Financial advisers (adviser channel)coreUK financial advisers introduce clients to Flagstone via the /advisers portal and partner-with-us programme. Referrals via advisers do not qualify for the Invite a Friend programme.
- CloudflarecoreCloudflare provides essential security and bot management cookies (__cf_bm) used across flagstoneim.com.
- AkamaicoreAkamai provides performance and bot-differentiation cookies (ak_bmsc, bm_sv) used on flagstoneim.com to optimise website performance and security.
- Microsoft AzurecoreMicrosoft Azure provides load-balancing cookies (BNES_ARRAffinity, BNES_ARRAffinitySameSite) for secure session routing in production environments.
- Heap AnalyticscoreHeap provides product analytics cookies for tracking user interactions, sessions, landing pages and referrers across the platform.
- HotjarcoreHotjar provides session and user behaviour analytics cookies used for product analytics and UX research on flagstoneim.com.
- Salesforce / PardotcoreSalesforce Pardot provides B2B marketing automation cookies (visitor_id, lpv, BrowserId_sec) for prospect tracking and lead nurturing on flagstoneim.com.
- Google Analytics / Google Ads / YouTubecoreGoogle provides analytics, advertising and embedded video cookies (GA, _gcl_au, APISID, SID, NID etc.) across flagstoneim.com for measurement and retargeting.
- ABTastycoreABTasty provides A/B testing and personalisation cookies used to improve the user experience on flagstoneim.com.
- CIFAS (fraud prevention)coreFlagstone shares personal information with CIFAS fraud prevention agencies to prevent fraud, money laundering, verify identity and detect crime.
Scale indicators8 records
Recent moves6 records
Expansion highlights6 records
Flagstone competitors and assessment
Company assessmentDirect peers
- Raisin: Raisin operates a savings marketplace that aggregates deposits across multiple European banks under a single platform — the closest international analogue to Flagstone's multi-bank cash deposit model, with overlap in partner-bank aggregation and FSCS-equivalent deposit protection.
- MoneySupermarket Group: UK price comparison and savings marketplace — and notably a shareholder in Flagstone (per 2020 funding round). Competes directly in the savings comparison and switching space that feeds Flagstone's top of funnel.
Broad incumbents
- Hargreaves Lansdown: UK's largest direct-to-consumer investment and savings platform; while broader than Flagstone (funds, shares, pensions), it offers a Cash Savings offering that competes for the same FSCS-spreading, multi-bank saver use case.
- AJ Bell: UK investment platform with cash savings and SIPP capabilities; overlaps with Flagstone in offering a consolidated cash plus investment proposition to UK savers and advisers.
- Marcus by Goldman Sachs (UK): Goldman Sachs' UK digital savings brand offering FSCS-protected easy-access and fixed-term accounts; a direct substitute for many of the products Flagstone aggregates, with comparable rate positioning.
Emerging players
- Atom Bank: UK challenger bank with a strong fixed-rate savings franchise; competes for the same high-value saver segment and is itself a partner bank on the Flagstone panel, illustrating both competition and channel relationship.
- Zopa Bank: UK digital bank with savings products targeting similar HNW and mass-affluent savers; overlaps with Flagstone in interest-rate-led acquisition and FSCS-protected deposit accounts.
- Moneybox: UK consumer savings and investment app offering Cash ISA and easy-access savings alongside investing; overlaps with Flagstone on the Cash ISA proposition following Flagstone's February 2026 launch.
Regional players
- Wealthsimple: Canadian digital wealth platform with cash and savings accounts; comparable business model (multi-product, API-integrated, regulated) but operating in a different geography than Flagstone's UK core.
Others
- ClearBank: UK clearing bank providing banking-as-a-service infrastructure to fintechs; an enabler and potential partner/competitor at the infrastructure layer that supports digital savings propositions similar to Flagstone's API ecosystem.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat6 records
Key risks6 records
Key highlights7 records
Customer concentration
Flagstone social profiles
Digital presenceFlagstone compliance and trust
Trust signalCompliance6 records
Flagstone financial estimates
Financial estimateRevenue estimate
Valuation estimate
Flagstone leadership team
Management profileNumber of profiles
Profiles5 records
Flagstone subsidiaries and ownership
Company hierarchySubsidiaries1 record
Flagstone funding detail
Funding detailFunding overview
Funding rounds5 records
Investors6 records
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Flagstone M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Flagstone
What does Flagstone do?
Flagstone operates an FCA-authorised cash deposit platform that aggregates 450+ savings accounts from 65+ UK partner banks into a single customer interface, enabling individuals, businesses, charities and adviser-introduced clients to spread deposits for higher interest and up to £120,000 FSCS protection per banking group. The consumer platform is complemented by an enterprise REST API suite used by pension providers, wealth managers and SIPPs to access 60+ banks through one integration, plus a bank panel programme that lets UK banks distribute their savings products on Flagstone's platform. The company earns revenue via a share of the interest paid by partner banks on each account opened through the platform, with no fees charged to end users.
Is Flagstone a public or private company?
Flagstone is a private company. It is classified as venture growth investor backed and is currently operating.
When was Flagstone founded?
Flagstone was founded in 2013. It employs 251 to 500 people.
Where is Flagstone based?
Flagstone is headquartered in London, United Kingdom, in the Europe region.
How does Flagstone make money?
Two revenue lines are on record. Share of interest from bank partners are the primary driver. The others are API partner revenue from financial institutions.
Who are Flagstone's main competitors?
Direct peers on record are Raisin and MoneySupermarket Group. Broad incumbents are Hargreaves Lansdown, AJ Bell and Marcus by Goldman Sachs (UK). Emerging players are Atom Bank, Zopa Bank and Moneybox. Wealthsimple is listed as a regional player. ClearBank is listed as an others.
Does Flagstone have an API?
Yes. Flagstone exposes a suite of five REST APIs documented to OpenAPI 3.0 specification for partner financial institutions (pension providers, wealth managers, platforms) to embed multi-bank savings into their own products. API suite includes: Client API (onboarding and management of individual and company clients, version 2020-08-01), Product Catalog API (browse savings products/rates/terms, version 2022-07-01), Instruction Request API (deposits, withdrawals, account closures, reverts, version 2021-11-01), Portfolios API (view client savings positions, version 2020-04-01), and Instruction Batches API (daily settlement cycle visibility). Authentication is via API key in `cdpapi-Subscription-Key` header. Both sandbox (api.sandbox.flagstoneim.com) and production environments are available. Supports GBP, EUR, USD currencies. Sustained throughput up to 50 requests/second with built-in idempotency and optimistic concurrency versioning. FCA authorised and regulated. In production since 2019, processing 100M+ instructions annually with £100bn+ capital transferred to date. Developer documentation is at api-docs.flagstoneim.com.
What industry is Flagstone in?
Flagstone's product category is Cash Deposit Platform. Its primary akta.pro industry code is FSAGAAAD, Digital Wallets & Account Aggregation Hub (Multi-account, Stored Value), with a secondary code of FSABAAAA, Mass-Market Consumer Deposit Banking (Checking/Savings). Its NAICS code is 5221 and its SIC code is 6099.