Round vs Flagstone: which is right for your business cash? (2026)
Copied! Flagstone spreads idle cash across FSCS-protected banks; Round earns money-market yield and runs treasury, payroll and invoices from one place. A practical guide to which one fits how you actually manage cash.
Flagstone and Round both stop business cash sitting idle, but they are not the same kind of product. Flagstone is a deposit marketplace that spreads your balance across FSCS-protected banks. Round is a finance platform that earns yield and also runs the payments, payroll and reconciliation work around it. Which one fits depends on whether your problem is the rate or the workload.
TL;DR
- Flagstone spreads cash across 40-plus FSCS-regulated banks, £100,000 minimum, fixed business rates up to around 4.40% as of June 2026.
- Round routes idle cash into an institutional money market fund with BlackRock with same-day liquidity*, and ALSO offers its own FSCS-eligible Savings product.
- Only Round runs accounts payable, UK payroll and multi-entity cash from the same place.
- Pick Flagstone if FSCS-protected deposits are the whole job and you want the simplest thing to explain to trustees.
- Pick Round if you are moving money by hand before every payment run.
So Round gives you a choice Flagstone cannot: FSCS-protected deposits, higher-yield money market funds, or both at once, inside a platform that also runs your AP, payroll, and cash operations. The comparison below covers both routes.
What is Flagstone, and who is it for?
Flagstone is a cash deposit marketplace, not a bank. You sign up once, pass a single KYC check, and gain access to a menu of savings accounts from 40-plus FCA-regulated UK banks, all held through a central holding account (provided by HSBC). You move money between instant-access, notice, and fixed-rate accounts without reapplying at each bank. Flagstone makes its return by taking a margin on the interest before passing rates on to you.
The business proposition is simple: spread a large idle balance across multiple partner banks, keep each tranche below the FSCS protection limit per banking group, and earn better rates than a single high-street relationship can offer. As of June 2026, Flagstone advertises fixed-term business rates up to around 4.40% AER on 12-to-18-month terms. The business entry point is £100,000.
Flagstone is good at its one job. If you have a large sum sitting idle and your priority is FSCS-protected, multi-bank deposit coverage at competitive rates, Flagstone is built for that. It is used by SMEs, charities, wealth managers and institutional clients.
What Flagstone does not do: it cannot pay a supplier, fund a payroll run, reconcile an invoice, convert a currency, or automate any finance workflow. Money goes in. Money earns interest. That is the product.
What is Round, and who is it for?
Round is a finance automation platform: treasury yield, accounts payable, UK payroll, multi-entity cash visibility, and FX in one system, with AI agents that handle approval routing, cash sweeps, and payment execution.
On the yield side, Round sweeps idle cash into the BlackRock ICS Sterling Liquidity Fund, an institutional-grade AAA money market fund. Round states an average of 4x the yield of a standard business savings account. Rates move with the market and are shown live on Round's pricing page, so check roundtreasury.com/pricing rather than relying on a number printed here.
Withdrawals must be requested by 10:30am for same-day liquidity. Round holds customer assets in segregated accounts with regulated partners, including WealthKernel's investment infrastructure and BlackRock as fund manager, and does not hold customer money on its own balance sheet.
Crucially, Round is not a money-market-only platform. Alongside the fund, Round runs its own FSCS-eligible Savings product, built on Insignis, to which Round is an Introducer, and which spreads deposits across a network of UK partner banks in the same way Flagstone does, and carries the same FSCS protection: up to £120,000 per institution (assuming eligibility), extending to up to £3.5m in aggregate once spread across enough partner banks.
So Round gives you a choice Flagstone cannot: FSCS-protected deposits, higher-yield money market funds, or both at once, inside a platform that also runs your AP, payroll, and cash operations. The comparison below covers both routes.
Beyond yield, Round handles the finance work that deposit platforms cannot touch. Invoices arrive by email, WhatsApp, or upload, get AI-coded and checked for duplicates, and are approved through configurable rules before Round pulls funds from treasury and settles on the due date, keeping cash invested until the last possible moment.
Every payment syncs automatically to Xero or NetSuite. Payroll works the same way in reverse: Round doesn't calculate salaries, it pays what your existing payroll provider has already worked out. Upload the file, route approvals, and Round funds the run from treasury and executes on pay day.
Round also gives multi-entity finance teams a consolidated dashboard across UK, EU, and US bank accounts, with real-time cash positioning and live export to Google Sheets or a data warehouse. Those bank connections run through Plaid, for which Round acts as an agent.
FX is built into the product, and is available across GBP, USD, and EUR.
Round is built for UK finance teams that want idle cash working harder and the operational work automated: venture-backed companies, CFOs managing multiple entities, and founders who want to remove manual steps from payroll, AP, and treasury without stitching together five separate tools.
How do Round and Flagstone compare?
Which protects your cash better, FSCS deposits or a money market fund?
This is the most important section to read carefully before choosing.
Flagstone gives you FSCS-protected deposits. Every partner bank is FCA-regulated and FSCS-eligible. By spreading your balance across multiple banks, Flagstone keeps each tranche below the per-banking-group FSCS limit. If a partner bank fails, each protected tranche is covered up to that limit. That is one of the clearest forms of UK depositor protection available to a business.
Round's money market product gives you a fund, not a deposit account. The BlackRock ICS Sterling Liquidity Fund is an institutional AAA-rated fund investing in short-term, high-quality instruments. Your money is held in segregated accounts and does not sit on Round's balance sheet, but this is asset protection, not FSCS coverage.
Round states plainly that your capital is at risk, and that FSCS does not cover e-money products. Round Financial Limited is authorised and regulated by the Financial Conduct Authority, FRN 1050315, and is certified to ISO 27001:2022.
Those tell you the operator is supervised and its security is externally audited. Neither changes the protection model of the fund itself, which is the thing to weigh here.
Money market funds are widely used by UK corporates and finance teams for near-cash yield, and a AAA-rated fund has a strong structural track record. But the protection model is different from a bank deposit, and you should understand that before moving funds.
If FSCS cover matters more to you than MMF yield, remember Round's own Savings product (via Insignis) offers the deposit-spreading route too, just as Flagstone does.
The like-for-like: on FSCS-protected deposits, Round matches Flagstone. Its Savings product uses the same partner-bank spread, up to £120,000 per institution and up to £3.5m in aggregate. Everywhere else the table is one-sided. Flagstone does deposits and nothing else: no accounts payable, no payroll, no multi-entity cash visibility, no FX, no AI agents. Round does all of it, and adds a higher-yield money market route on top. So the real question is not who protects deposits better, since both do, it is whether you want a single-purpose deposit marketplace or a finance platform that also protects deposits.
Neither platform is a replacement for your main bank account. Both are purpose-built for idle cash above a certain scale.
When should you pick Flagstone?
Flagstone is the right answer when:
- Your main job is parking a large sum (£100,000 or more) in FSCS-protected deposits at competitive rates, and you have no need for AP, payroll, or cash ops automation.
- You manage cash for a charity, trust, or institutional client where FSCS protection is a governance requirement.
- Your finance team is small and a simple, single-purpose savings platform is the easiest thing to onboard and explain to trustees or auditors.
- You want fixed-term rates rather than a variable money market yield.
Flagstone does its one job well. If that is your job, use Flagstone.
When should you pick Round?
Round is the right answer when:
- You want idle cash earning institutional-grade yield and you also need AP, payroll, or multi-entity cash management automated in the same system.
- You are a CFO or finance lead at a UK growth company managing cash across multiple entities, currencies, or bank relationships.
- You fund payroll or supplier runs from a central treasury balance and want to stop moving money manually between accounts before each run.
- You use Xero or NetSuite and want every payment reconciled automatically, without a manual step.
- You are comfortable with a money market fund protection model (asset-protected, not FSCS-deposit-insured) for the treasury product, or you'd rather use Round's own FSCS-eligible Savings option instead.
One practical note before either shortlist. Round is a young company, founded in 2023, so apply the diligence you would apply to any newer provider holding your cash. Ask for the same pack you would ask a bank for, and ask to speak to a reference of similar size. Many teams start with a single tranche rather than the whole balance, and that is a sensible way in.
So the choice comes down to what your problem actually is.
Flagstone is excellent at one job, spreading a large balance across FSCS-protected banks. Round does that same job through its Savings product, and if you also want yield, accounts payable, payroll, multi-entity cash and FX handled in the same place, that is where the platforms stop being comparable.
A useful test: look at what your last month-end actually cost you in hours.
Related reading
- Best places to park idle business cash in the UK (2026): read this if you want the wider market before deciding. Flagstone, Round, Insignis, TreasurySpring and the major money market platforms compared on yield, protection and minimum.
- How Round automated payroll and AP for Jack & Jill: read this if the workload is your problem rather than the rate. A UK finance team moved £14M off 0.65% at Tide and removed its manual payment runs.
Ready to see Round in your finance stack? Book a demo: 30 minutes with the team, tailored to your entity structure and current stack.
Frequently Asked Questions
It depends on what you are trying to do. Flagstone is better if your goal is FSCS-protected deposits spread across 40-plus banks at competitive fixed rates, with a £100,000 business minimum and no need for AP, payroll, or cash ops. Round is better if you need yield plus an automated finance function, and it can also match Flagstone's FSCS-spread approach through its own Savings product. They serve different buyers.
Round holds customer assets in segregated accounts with regulated partners and does not hold money on its own balance sheet. Round Financial Limited is authorised and regulated by the Financial Conduct Authority (FRN 1050315). The underlying fund on the treasury side, the BlackRock ICS Sterling Liquidity Fund, is an institutional AAA-rated money market fund, and this is asset protection, not FSCS deposit insurance: Round states clearly that your capital is at risk on that product. If FSCS-deposit coverage is a hard requirement, Round's own Savings product or a deposit platform such as Flagstone are the appropriate routes.
No. Flagstone is a deposit marketplace. Money placed with Flagstone sits in savings accounts and earns interest; it cannot fund payroll or supplier payment runs. Round's payroll product funds each run directly from the treasury balance, with multi-entity approval workflows and settlement on pay day.
Round routes idle cash into the BlackRock ICS Sterling Liquidity Fund and states an average of 4x the yield of a standard business savings account. Exact net AER by plan is shown live on roundtreasury.com/pricing and updates with the market, so check there for today's figure rather than a number printed in an article.
No. Flagstone has no AP, payments, or finance-ops capability. It is a deposit-only product. If you need automated invoice capture, coding, approval routing, and funded settlement, that is Round's accounts payable product, which syncs every payment to Xero or NetSuite automatically.
The business minimum on Flagstone is £100,000. There is no stated maximum. The personal minimum is lower (£10,000), but business and personal accounts are separate products. Flagstone is not suited to smaller cash balances.
Flagstone does not charge a platform fee directly. Instead, it takes a margin on the interest rate before passing it to you (reported figures for this margin vary, so check Flagstone's own referral terms rather than a fixed number). Round's Launch tier is free to start, with Growth and Enterprise on quote-based pricing, plus per-transaction fees for invoices, payroll overage, and FX that vary by plan; see roundtreasury.com/pricing for current figures on both.
No. Round is a finance automation and treasury platform, not a current account provider. It sits alongside your existing bank accounts, connecting them for visibility and routing payments from treasury. Similarly, Flagstone is not a bank account; it is a marketplace for savings products held at partner banks.
