Most of us go through the same progression on the way to taking our finances seriously. You start with one account, so keeping track is easy. Then a second, a third, checking two or three banking apps and doing a bit of mental math to get to a final number. At some point the number of accounts and the complexity outgrows what you can hold in your head, and you build a spreadsheet.
I've been through this enough times to have opinions about it. Over the past couple of years I've actively, and semi-actively, maintained five different versions of a net worth spreadsheet. Some worked better than others. All of them eventually showed the same cracks. Here's what I've learned from running that experiment five times over.
Before getting into where it falls apart, it's worth being honest about why it works as well as it does for as long as it does.
Aggregation. One number, pulled together from every account you own. You can set basic goal targets against it, and if you're spreadsheet-savvy, add a partner's accounts too. It's a real step up from switching between three or four banking apps and doing the maths yourself.
Cost. It's free, assuming you already have spreadsheet software, and there are decent open source alternatives if you don't.
Control. You own every formula. Nothing about your net worth depends on a company staying in business or deciding to keep your data around.
Privacy. Run it locally and your data never leaves your machine, and you're not sharing a single login with anyone. Cloud spreadsheets are a bit different: most weren't built with financial-data-level security in mind, so that trade-off is worth thinking about before you move your whole net worth into one.
Personalisation. You're not waiting on a product team to ship the feature you need. If you can build it in a formula, you can track it. That flexibility is real, and it's only limited by how good you are with a spreadsheet.
Five spreadsheets in, the failure modes stopped surprising me. They're consistent enough that I'd bet money on which one gets you first.
Update frequency drops off. Everyone starts with full energy: a new tab, a clean structure, updates every week. I've watched this happen to myself and to friends enough times to know how it goes. A few months in, the updates get less frequent, then occasional, then you're squinting at numbers from months ago trying to remember what actually happened. That gap doesn't just mean an out-of-date total, it means you lose the ability to see what worked and what didn't.
Prices go stale, and currencies multiply faster than you'd expect. Unless you're running a cloud spreadsheet with live data feeds, and plenty of people avoid that for the privacy reasons above, your investment values are only as current as your last manual update. Currency adds another layer: buy US stocks from the UK and you're already at two currencies. Add an account back in a home country as an expat and you're at three. Throw in RSUs from an overseas employer and you're at four. None of this requires you to be a sophisticated investor, it's just what a normal financial life looks like now.
The mistake that's easy to make and hard to catch. I've spent enough years around code to know that more lines almost always means more bugs, even from good engineers. A spreadsheet behaves the same way. Add enough formulas, enough tabs, enough data, and something a few sheets down will quietly break without telling you. I've added a new row for an investment and had it miss the subtotal above it. I've had a copied formula silently pull from the wrong cell. Every time you change the structure of the sheet, and eventually you will, you need to go back and cross-check it. That's not a one-off task, it's ongoing.
Deeper portfolio analysis gets hard. Once you want more than a total, geography spread, asset class spread, account costs, that becomes difficult to maintain by hand once you're holding multiple funds and ETFs, each with their own underlying constituents.
The maintenance time creeps up. As the sheet grows, so does the time it takes to update properly. And because you're updating it irregularly, you don't remember the structure as well each time, which slows you down further. It compounds in the wrong direction.
Scenario modelling can quietly lie to you. A spreadsheet will happily model any future you want, retirement in fifteen years, downsizing at sixty, whatever assumption you throw at it. But get one input wrong in a multi-year formula chain and the error compounds every year forward, giving you false confidence in a number that's actually wrong. It's a DIY problem: you don't know what you don't know, and there's no one checking your modelling against anything more rigorous than your own assumptions.
This is usually where posts like this pivot straight into a pitch, so let me deal with the objection first instead of skipping past it.
Handing your financial picture to an app means sharing account access with a third party, and that's not nothing. The good news is that this isn't the same trade-off it was ten years ago. In the UK, Open Banking means you're not handing over your actual bank login the way older screen-scraping tools used to require. You authorise access directly through your bank, and the app never sees your credentials. That's a meaningful, checkable difference, not just a reassurance. Apps built for financial data also tend to be designed with that specific security bar in mind, which is more than you can say for a spreadsheet built by someone with no background in it.
I'll be honest about the other side too: not every institution connects with the same speed or reliability. Some banks sync cleanly, others lag. That's a real limitation of the category, and worth knowing going in.
None of this means the spreadsheet was a waste of time. It solved a real problem, and building one is usually a sign you've started taking your financial planning seriously enough to want a proper answer. It's also as flexible as you are, which is exactly the appeal.
But as your accounts and your history grow, the time cost and the error cost stop being minor annoyances and start being the actual story. Deep portfolio analysis and scenario modelling are things a spreadsheet can technically do, but doing them correctly, and doing them regularly, is a different question. That gap, between what's technically possible in a spreadsheet and what you'll actually keep doing well for years, is where a proper aggregator earns its place.
Gild connects to your accounts over Open Banking, the same way described above, so it never sees your login and stays current without you doing the manual update every month. And if you want your partner or family to see the same picture, that's a built-in shared view, not another tab to maintain by hand.
Everything in one place: your banks, pensions, investments, and goals.
🔒 Your data, never sold. Always protected.