Accounts Assistant - 6 month FTC in London

Flagstone is an online savings platform, reinventing how individuals, businesses, and charities manage, protect, and grow their cash. Behind that mission is a diverse team of people bound by a collaborative spirit — and a business that's profitable, ambitious, and genuinely good at what it does. What ties it all together is our culture. It's our competitive advantage, and we guard it carefully.

A feel for our culture: High performance needs more than talent. It needs an environment built on kindness, respect, and the freedom to grow. We're building a diverse, inclusive community where your voice carries weight, your development is taken seriously, and your contribution is recognised. We may not change the world. But we're changing the world of savings — and we'd like you to be part of it.

The Finance Team is led by the CFO and structured across two specialist areas: FP&A, which partners with the business on planning, forecasting and commercial decision-making; and Financial Control, which owns the integrity of our numbers, core operations, and financial controls. This role sits within Financial Control, reporting directly to the Financial Controller.

As Accounts Assistant, you'll keep the engine running. You'll be the first point of contact for finance queries, own the purchase ledger end-to-end, support month-end close, and help manage corporate cash movements and reconciliations. Process matters here — and so does the judgement to know when to escalate. You'll work closely with the Financial Controller and Head of Finance, contributing to audits, payroll processing, and identifying where things can be done better.

What you’ll do:

• Accounts payable and receivable
• Process supplier invoices accurately and on time, ensuring correct coding and authorisation
• Raise sales invoices and manage the collection of outstanding debts
• Monitor aged debtors and creditors, escalating where appropriate
• Process and reimburse employee expense claims in line with company policy and HMRC guidelines
• Bank and cashflow
• Perform daily bank reconciliations across multiple accounts
• Post cash receipts and payments to the ledger
• Assist with cashflow monitoring and reporting
• Month-end and reporting
• Support the month-end close process, including journal postings and accruals
• Assist with the preparation of management accounts and financial reports
• Maintain fixed asset registers and process depreciation entries
• Produce ONS reports
• General finance administration
• Maintain accurate, up-to-date financial records and filing systems
• Respond to internal and external finance queries professionally and promptly
• Assist with year-end audit preparation and provide supporting documentation
• Identify opportunities for process improvement across the finance function

What you’ll bring:

Must haves:

• At least one to two years' experience in an accounts or finance role
• Solid grounding in double-entry bookkeeping and core accounting principles
• Confident in Excel — VLOOKUPs, pivot tables, and standard formulas
• Experience with accounting software such as Workday, Xero, QuickBooks or similar
• Strong numerical accuracy and exceptional attention to detail
• Clear, organised, and able to manage a varied workload without losing pace

Nice to haves:

• Previous experience in a similar industry or finance shared services environment
• AAT Level 2 or above, or part-qualified ACCA or ACA
• Familiarity with cloud-based accounting platforms
• An interest in learning SQL for data querying and financial reporting

How we reward you:

At Flagstone, the benefits extend beyond false gifts like “fruit and snacks”. Instead, we invest in your health, wealth, and professional development. Here’s a selection of our benefits:

• Hybrid working — at least one day a week in our London office
• Flexible benefits budget — spend it on what actually matters to you
• Salary sacrifice options: electric cars, nursery schemes, home and tech goods
• Mental wellbeing support via Spill
• £1,000 personal development budget
• Private healthcare with AXA, including reduced gym memberships
• Medical cash plan for dental and optical costs
• Life insurance and income protection — four times your annual salary
• Matched pension contributions up to 5%
• 25 days holiday, plus bank holidays, wellbeing days and volunteering days
• Enhanced maternity, paternity and adoption leave

At Flagstone, we're building a team that challenges what finance looks like. We encourage you to apply — whatever your background.