How I spent a month moving 40 years of ledger books into one spreadsheet

Earlier this year, I got a call from a client's representative. They asked me to compile last quarter's sales data and send it over by the end of the day. A simple task. It should have been. I opened my desk drawer and pulled out three ledgers: sales, purchases, and expenses. As I flipped back and forth between them, cross-checking figures, an amount on one page of the expenses ledger didn't match a note in the sales ledger. There were even parts where I couldn't read my own handwriting. I didn't get the materials sent on time that day, and I could hear the disappointment in the client's voice.

I've been using paper ledgers for close to 40 years, ever since I first opened my office in Incheon. Writing in pencil, erasing, writing again — the process felt like a ritual for pressing the numbers into memory. No matter how convenient digital tools became, I believed there was a trustworthiness to handwritten ledgers. Or, to be precise, it wasn't trust. It was familiarity.

Why I couldn't let go of the ledgers

Looking back, my attachment to paper ledgers was a kind of safety net. What if the computer shuts down? What if the files get wiped? I repeated those worries like a reflex. But what actually got me into trouble wasn't a computer malfunction — it was the problem of not being able to tell my handwritten 7s from my 1s. There was also the inefficiency of flipping across three ledgers, recording the same transaction three times. I spent just over 50,000 won a year on office supplies alone — pens, correction tape, ledger books — but the cost wasn't the issue. The issue was that those items were taking over my drawers and desk.

For a few days after the client incident, I went back and forth. My son had been telling me for years to try Google Sheets, but every time, I'd turned him down: "I have my own way of doing things." This time, there was no excuse left.

What happened after I decided to make the switch

I called my son and asked him for some time over the weekend. It took two days to learn the basics — entering numbers into cells, using functions to calculate totals, dividing sheets to organise items by category. Honestly, it wasn't hard. The hard part was somewhere else entirely.

Once the work of transferring old ledger data began in earnest, I ran into emotions I hadn't expected. When I opened the 2019 ledger, there in one corner was a scribble: "Had good bibimbap for lunch today." In the 2015 ledger, the month I first exceeded 10,000,000 won in monthly sales had a red underline drawn beneath it. My time was wedged between the numbers. Getting rid of the ledgers felt like getting rid of that time, too.

But I'm an accountant. I know that accuracy comes before the luxury of sentimentality. Over the course of a month, I transferred the most recent five years of data into a single spreadsheet. I kept the structure simple: sales, purchases, expenses, and a monthly summary. Four tabs in total. In the past, I would have broken it down further, but this time I made it simple on purpose — because 40 years had taught me that the more complicated you make something, the less you end up using it.

One month later: what changed

The first change I noticed was speed. When a client requested materials, a single search was all it took. The time I used to spend flipping through three ledgers, repeating "just a moment" — that was gone. The relationship with the client I'd nearly lost steadied again as well.

My desk looked different, too. Three ledgers, a pen holder, correction tape, a ruler — once those were gone, nearly half the desk surface was empty. I briefly felt the urge to fill the space with something, but I left it as it was. An empty desk makes my head feel a little clearer. A baseless impression, maybe, but at least for me it holds true.

I didn't throw away the old paper ledgers. I put them in a box and placed it on a shelf in the corner of the office. I'll never pull them out again for work, but there's no need to throw away that red underline and the bibimbap scribble along with them.

If I have one regret, it's that I didn't make the change sooner. Then again, that "sooner" probably never existed. Until I got that call from the client and felt firsthand that my way of doing things could cause problems for someone else, no amount of persuasion would have worked. You only move when discomfort crosses a threshold. At least, that's how it was for me.