Operating Model & Finance Process Advisory
We help growing businesses and charities replace spreadsheets and firefighting with the operating model and finance processes that let them scale — and the numbers to make good decisions.
The Problem
Most growing organisations hit the same wall somewhere between 5 and 250 people. The spreadsheets and habits that worked when it was just you and a few trusted people start to creak. Sound familiar?
A client sits on your invoice for weeks — on average UK small businesses are owed £22k and wait 32 days past terms — and you only notice when the bank balance looks wrong.
Month-end close eats a week or two of your best people's time, every single month.
Someone quits, or two people double-book the same job, and suddenly it's obvious nobody actually owned it.
You've clearly outgrown the spreadsheet — but a full-time Finance Director or COO feels like a lot of overhead to take on.
Making Tax Digital lands in April 2026 for anyone with business income over £50k — and most businesses this size aren't ready for digital record-keeping and quarterly submissions.
You've tried an AI tool or two, or been told you should — but nothing's really stuck, because the process and data underneath it were never fixed.
“That gap — between founder-led and properly scaled — is exactly where we work.”
We work with manufacturing & distribution, professional & business services, construction & trades, retail, consumer and hospitality businesses, and charities across the UK.
In Practice
One common fix, start to finish — this is the kind of thing a Diagnostic surfaces.
Before
Month-end close: five spreadsheets, three people quietly cross-checking each other's numbers, and a week gone before anyone fully trusts the total.
After
Month-end close: one source of truth, a defined checklist, and numbers leadership can act on within days — because everyone agreed upfront who owns what.
What We Do
We don't try to be everything to everyone. We focus on the two areas that decide whether a growing business scales in control, or scales into chaos.
01 — Operating Model
We map how work really happens — not how the org chart says it happens — clarify who owns what, and fix the data quality issues that quietly undermine every decision built on top of them. The same discipline used to design enterprise operating models and data governance, scaled down to fit a business your size.
02 — Finance Process
We fix the mechanics of how money and information move through your business — so month-end stops being a fire drill, and your leadership team gets the numbers it needs to make good decisions, on time.
How We Work
"Hire a consultant" has a mixed reputation with business owners — vague scope, a big invoice, thin follow-through. That's exactly why we don't ask you to commit to anything open-ended. You start with a fixed fee and a clear point to stop — or continue — at every stage.
A focused review of your operating model and finance processes, benchmarked against how well-run businesses your size operate. You get a clear, ranked list of what to fix first — not a lengthy report that sits on a shelf.
We implement the specific fixes agreed in the diagnostic — redesigned processes, a reporting pack, a budgeting cycle, clearer roles and ownership — working alongside your team so the changes actually stick.
Ongoing, part-time COO- and FD-level advisory, billed monthly like any other retained service — senior finance and operations input, without the cost or commitment of a full-time hire.
Why Us
Between us, we've spent over 20 years building the operating models and finance functions that some of the largest financial institutions in the world rely on. We're a brand-new firm working with businesses your size — no client list yet, no pretending otherwise — but the discipline behind that experience translates directly, at a scale, pace and price that actually fits.
Designed operating models that let functions scale without proportional headcount growth
Built reporting and dashboards that gave leadership real-time visibility into performance
Delivered real efficiency gains through process redesign — the same discipline, sized down to fit a business your size, not a scaled-up version of what worked at a bank
Redesigned finance processes that cut close cycles and freed up decision-making time
20+ years fixing the same problems inside some of the world's most complex organisations — now applied to growing businesses, without the enterprise price tag
Combined MBA (London Business School) and qualified accountant (ACMA) expertise
About Us
Nathan Brothers was founded by siblings Llavan and Thamy Sivaloganathan, who spent their careers on opposite sides of the same problem: how large, complex organisations actually get things done. We started this firm to bring that combined view to growing businesses that don't have it in-house yet.
Llavan Sivaloganathan
Operating Model, Programme Delivery & Process Design
Llavan has spent over 20 years leading complex change programmes at major UK and global financial institutions, managing budgets of up to £40m and teams of 60 or more. He specialises in turning big, ambiguous goals into practical delivery plans — redesigning how organisations work, clarifying who owns what, and building operating structures that let a business grow without adding layers of management for the sake of it.
MBA, London Business School · MSc Information Technology & BSc (Hons) Mathematics, University College London
Thamy Sivaloganathan
Finance Process, Business Management & Operational Readiness
Thamy has spent over 20 years in financial services business management and finance business partnering, including senior COO and Chief-of-Staff roles managing budgets of up to €15m. She has designed the target operating models, governance and reporting that let finance and investment teams launch new products and run smoothly at scale — and now translates that same playbook for growing SMEs.
ACMA, Chartered Institute of Management Accountants · MSc Information Technology, University College London
Get In Touch
The first conversation is free, and there's no obligation. Tell us a bit about your business, and we'll come back with some honest thoughts — even if that's just pointing you in the right direction.
