Love is patient until money is involved. It’s a principle my partner and I live by, especially early in a relationship when anything can feel like a red flag.
I’m learning to apply it to other interactions. Recent group outings taught me to set boundaries without disrupting the budget systems we already had.
It’s never nice when someone pays for everything on the day, and everyone agrees to sort it out later, only for nobody to pay.
So I built an automated bill-splitting system in Google Sheets that does the chasing for me.
Money made me rethink my relationships
Because breakups can have financial causes
My partner and I have been dating for a month, and have set financial boundaries. No one is entitled to each other’s money because we’re both working.
We happily spend money on each other on date nights, and have a system of reciprocity that works for us. It’s something I’ve struggled to do with friends.
Before, I got used to lending out amounts I could afford to lose. But because nobody wanted to bring up repayments, it became easier for everyone to get away with avoiding it.
Even when we braved the hard conversations, all parties ended up looking petty. The amount was small enough that demanding it seemed more important than the friendship.
These days, I’ve learned a lot about self-esteem and its ties to personal finance. It’s made me confident to ask for my money back without apologizing for it.
It’s bizarre that I even had to feel this much self-reproach to retake what’s mine. I now run a strict program with money, and ensure everyone else complies.
Sheets is surprisingly handy for this purpose, especially for someone who dreads data entry and doing calculations.
My phone is crammed with many apps
I didn’t need another budgeting app
I needed a solution tied to an existing tool because I already used too many tools. Google Sheets immediately came to mind because I use it to log invoices.
The Apps Script add-on complemented it, being Google’s built-in JavaScript editor under Extensions. It can read and write Sheets’ data, send emails through Gmail, and run itself on a set schedule.
I have a fair understanding of programming, so it didn’t take long to figure out the rest.
Email might seem like a slow choice when everyone lives on social media. But I check my emails more than my social apps, and my circle is similar.
They also leave time-stamped records and exist on a server rather than on someone’s phone. All parties hold independently retrievable copies, and neither can delete the other’s.
It’s why they’re harder to fabricate or dispute. In comparison, a WhatsApp message flattens the topic’s seriousness.
I once loaned $100 to a friend, who later decided it had been a “gift.” The texts where we had agreed otherwise had miraculously cleared from his end.
I dread manual labor
So, I made an AI system that does it for me
I created a new Google Sheets file and built the People tab first, setting up six columns for name, email, total paid, fair share, balance, and status.
Entering their email addresses allows the script to read column B and send reminders, turning the People tab into an automated mailing list.
Total paid uses SUMIF to add every expense where a person’s name appears in the paid-by column, and Fair share divides the total of all expenses by the number of people listed.
Meanwhile, Balance subtracts one from the other, and Status uses a single IF statement to determine whether someone is owed money or owes money.
I built this system with each person’s awareness, so nobody would be alarmed when the automated emails arrived. Then I fed Gemini a detailed prompt explaining my goal.
Example prompt: I have a Google Sheet that tracks shared expenses with friends. The People tab has columns for [enter your preferred column names] where [specify what each column does]. Write me an Apps Script that reads [your preferred tabs], skips anyone with no email or a zero balance, and emails everyone else the exact amount they owe or are owed, formatted in [your local currency]. Use MailApp so it sends through my own Gmail and no external services or libraries.
The AI tool generated 80 lines of JavaScript code, and on inspection, they were accurate. I copied them and navigated to Extensions > Apps Script in my spreadsheet.
You must open the add-on from inside your spreadsheet. Otherwise, creating a standalone project from its dashboard leaves the file unbound and causes active sheet calls to fail.
On the dashboard, I overwrote the placeholder function in Code.gs with my code before saving it. Then I named the project Bill Reminders.
Gemini included three functions in the file, and I selected sendBalanceReminders from the dropdown menu at the top of the editor.
Selecting the correct function matters because running the wrong helper function executes without dispatching emails.
I pulled some necessary triggers
Without them, I’d be firing blank emails
Running my script for the first time required authorization, which Google warned against.
Though it looked alarming, the warning is standard for custom scripts you create in Google Workspace rather than installing through the marketplace.
Selecting Advanced and proceeding to the script allows you to grant the necessary permissions. The test emails reached my secondary accounts within seconds.
Yet, I still needed to configure automated triggers. I clicked the clock icon and opened the Triggers menu in the left sidebar. There, I selected Add Trigger and filled out the pop-up form.
Then I set the function to sendBalanceReminders and left the deployment as Head. It was the only option unless I’d published versioned deployments of my script.
I didn’t need to because my project is a personal reminder, and the option points the trigger at the code currently saved.
Next, I chose Time-driven as the event source, selected Week timer, and set it for every Monday from 8am to 9am to avoid harassment. Then I clicked Save.
You may need to do another round of authorization after that.
If you use a pop-up blocker or ad blocker, it blocks the Apps Script form from saving. You should see a red notice at the bottom of the window. Whitelist script.google.com before you start to bypass it.
Afterward, the reminder is live, regardless of whether Sheets is open or not. When someone new owes money, I enter it in my spreadsheet, and they receive reminders automatically.
Sheets spreads further than you think
Building my bill reminder reminded me how capable Sheets is.
It can generate scannable QR codes with an IMAGE formula, pull live RSS feeds through IMPORTFEED, and translate text across columns using GOOGLETRANSLATE.
It can also fetch live currency exchange rates from Google Finance. Exploring the PC version is among the most effective places to test these capabilities.
