When someone sits across from me, worried about whether they’re in the right fund or holding too much cash, I almost always steer the conversation back to a quieter, less exciting place. Not the portfolio. Not the market. Their own monthly numbers. In decades of giving independent financial advice, I’ve found that investment tweaks without clear cash flow visibility are like adjusting the sails on a boat when you haven’t checked if the hull is leaking. You can fuss all day, but you’re still taking on water.
I’m Glynn Kerr, and my approach is fiduciary through and through. That means I’m obligated to put your interests first—not to sell a story about market-beating returns. And the truth is, most people don’t need a better stock pick. They need to know, with confidence, what’s coming in, what’s going out, and what’s left to protect the life they’ve built. The portfolio is just the engine room. Cash flow? That’s the hull.
The Real Foundation of a Financial Plan
Investment management gets the headlines. But a financial plan that holds up over time rests on something more basic: understanding your personal economy. Cash flow planning isn’t just a budgeting exercise. It’s a clear-eyed look at how money moves through your household—salaries, business income, taxes, recurring bills, debt payments, and the expenses that quietly inflate over time. I’ve sat with clients who had no idea their grocery spend had doubled over five years, or that subscription creep was eating £300 a month. That’s not a moral failing. It’s just what happens when life gets busy and nobody stops to look.
Without that picture, any investment decision is a guess. You might be taking on more risk than your cash flow can support. Or worse, you could be sitting in overly conservative investments because no one has shown you how much runway you actually have. I’ve seen both. The remedy isn’t a hot tip. It’s sitting down with a year’s worth of bank and credit card statements and mapping the reality. It’s tedious work. I won’t pretend otherwise. But it’s the only way to stop making decisions in the dark.
Why Sequence Matters
There’s an order to this work that I’ve found non-negotiable. First, stabilise the day-to-day. That means knowing your baseline monthly spend, isolating discretionary from non-discretionary costs, and building a cash reserve that fits your life—not some rule of thumb. I’ve met small business owners who needed a year’s buffer because their income was lumpy, and salaried couples who were fine with three months because their jobs were rock-solid. The textbook answer is rarely the right one.
When clients skip this step, I often find they’re holding too much in cash because they’re anxious, or they’re fully invested and one roof repair away from liquidating at the worst time. Cash flow planning removes that guesswork. It gives you permission to invest appropriately because you know the near-term is covered. That sense of permission is something I see people wrestle with. They think they’re being prudent by hoarding cash. Really, they’re just flying blind.
Investment Tweaks Are Usually a Distraction
I’ve lost count of how many people come in wanting to switch funds, chase a sector, or react to a market dip. That’s human nature. We’re wired to tinker. But when we pause and look at the cash flow statement, the real issue often surfaces. Maybe their savings rate has eroded because of lifestyle creep. Maybe a variable income stream needs smoothing before any long-term investing makes sense. Or maybe they’re simply paying too much in tax because no one aligned their drawdown strategy with their spending needs. These are the quiet killers of a financial plan.
These aren’t problems fixed by a better expense ratio. They’re fixed by reordering the priorities. Cash flow planning is what lets you see whether you’re saving enough in the first place. If you’re not, tweaking investments is like rearranging deck chairs—you feel busy, but the ship’s still going down. If you are, the investment conversation becomes simpler, and often more boring, which is exactly how I like it. Boring means you’re not reacting to headlines or chasing last year’s winner. Boring means the plan is working.
The Fiduciary Lens
Acting as a fiduciary means I can’t start with products. I have to start with you. Your cash flow tells me what you’re trying to achieve—college funding, a career change, leaving money to your kids—and what constraints you’re working within. From there, the investments become a tool, not the goal. That shift in perspective is often the most valuable part of the first few meetings. People walk in expecting a lecture on ETFs and walk out with a clearer sense of their own life. That’s not a downgrade. It’s the whole point.
It also means I’ll sometimes recommend doing nothing with the portfolio right away. Instead, we’ll build a deliberate spending plan, restructure debt, or rework insurance coverage. These moves can free up more capacity than a 1% portfolio tilt ever will. And they’re entirely within your control. A debt restructure that saves £400 a month—that’s real money. That’s a raise you give yourself. No fund manager can promise that kind of guaranteed return.
Retirement Isn’t a Number—It’s a Paycheck
One of the biggest mindset shifts I encourage is thinking about retirement not as a lump sum target, but as a reliable, inflation-aware income stream. That requires cash flow modelling that projects your spending, taxes, and income sources over decades—not just a Monte Carlo simulation on a portfolio balance. The latter looks impressive on a screen, but it doesn’t tell you whether you’ll be able to afford a new boiler in year twelve of retirement, or what happens if your travel budget doubles in the early years and then tapers off.
This is where cash flow planning and investment strategy finally meet. Once we know what your retirement paycheck needs to look like, we can design a portfolio that funds it without taking unnecessary risk. But if we start with the portfolio and try to back into a withdrawal rate, we’re doing it backwards. I’ve written before about the question you should be asking years before you retire, and it’s almost never “Am I in the right fund?” It’s “What does my spending actually look like, and how will I cover it when the paycheck stops?” That’s a harder question. It’s also the right one.
Modelling, Not Magic
Cash flow modelling doesn’t have to be complex. But it does need to be specific. I’ll often sit with clients and go through each line item, year by year, asking: Does this go up with inflation? Does it stop at a certain age? What about healthcare costs later in life? What about helping adult children? These aren’t investment questions, but they shape every investment answer. A client once realised they were over-saving by £600 a month because they’d never modelled a drop in housing costs once the mortgage was cleared. That’s a life-changing insight, and it had nothing to do with picking stocks.
The output is a plan that tells you, with reasonable confidence, whether you’re on track—and what levers you can pull if you’re not. Maybe you need to work two more years, but with a lower savings rate than you thought. Maybe you can retire sooner if you downsize. Maybe the portfolio can stay exactly as it is, and you can stop checking the market every morning.
The Practical Steps I Walk Through with Clients
If you’re reading this and wondering where to start, here’s the process I use. It’s methodical, not flashy.
- Gather the data. Twelve months of statements across all accounts. No averaging, no guessing. The detail matters.
- Categorise ruthlessly. Split fixed obligations from lifestyle spending. Be honest. This isn’t about judgement—it’s about clarity.
- Build a cash reserve. Tailored to your income stability and risk factors. Not the textbook six months, necessarily. I’ve seen people sleep better with two months and others who needed eighteen.
- Stress-test the plan. What happens if one income disappears? If interest rates rise? If inflation stays high? The point isn’t to be pessimistic; it’s to know the breaking points before they break.
- Align the portfolio. Only now do we discuss asset allocation, tax location, and drawdown order. The portfolio is the last piece, not the first.
This sequence protects you from the two biggest mistakes I see: taking too much risk when the cash flow can’t handle a setback, and taking too little risk when there’s ample capacity but no visible plan. Both feel safe in the moment. Both are quietly dangerous over time.
When the Markets Get Noisy
A cash flow plan is also the best defence against panic. When markets drop, and the headlines are shouting, you can look at your own numbers and see that your near-term spending is covered. That’s not just comforting—it’s actionable. It means you don’t have to sell into a downturn. It means you can stay invested for the long term because the plan doesn’t rely on this quarter’s portfolio value. I’ve had clients call me in a cold sweat during a correction, and within ten minutes of reviewing their cash flow, the sweat was gone. Not because the market recovered. Because they remembered they didn’t need the money for another seven years.
Without that foundation, every market move feels like a threat. With it, you can ignore the noise. That’s a freedom most investors never find because they skip the unglamorous work of cash flow planning. They’re too busy watching the ticker. Meanwhile, the quiet ones who did the homework are sleeping fine.
Common Questions I Hear
How is cash flow planning different from budgeting?
Budgeting tends to look forward with targets and restrictions. It’s aspirational—and often guilt-ridden. Cash flow planning looks at actual, historical patterns and projects them forward with realistic assumptions. It’s more about understanding your natural rhythm than imposing discipline. The goal is clarity, not constraint. I’ve seen budgets fail by February. A cash flow plan, rooted in what you actually do, tends to stick.
I already have a financial adviser. Shouldn’t they be doing this?
They should, but not all do. If your conversations are always about the portfolio and never about your monthly surplus or spending volatility, you’re missing a critical layer. A fiduciary adviser will anchor the relationship in your cash flow reality before making any investment recommendation. If your current adviser can’t tell you your average monthly net surplus, that’s a red flag.
Can’t I just use an app for this?
Apps can help you track spending, but they rarely provide the forward-looking, scenario-tested view that a professional cash flow plan offers. They also don’t connect the dots to tax strategy, estate planning, or the right portfolio structure. An app is a tool; a plan is a framework.
How often should I revisit my cash flow plan?
At minimum, annually. But you should also revisit it after any major life event—job change, marriage, divorce, birth of a child, or a significant shift in expenses. The plan isn’t static. It should evolve as your life does, which keeps the investment strategy aligned with your actual needs.
The Bottom Line
Investment tweaks have their place, but they’re never the first place. If you don’t have a clear, quantified understanding of your cash flow, you’re building on sand. That’s not a comfortable position for anyone, and it’s certainly not one I’d let a client stay in. Get the foundation right, and the investment decisions become calmer, more rational, and far more effective. The portfolio stops being a source of anxiety and becomes what it should be: a boring, reliable machine in the background.
So before you worry about whether you’re in the right fund, ask yourself: Do I really know my own numbers? If the answer isn’t a confident yes, start there. Everything else can wait.