How I Built BorderBook to Solve My Own Tax Residency Problem
For the last few years, my work has taken me across India and Southeast Asia more times than I can count. Singapore one month, Jakarta the next, back home to India, then off again. It sounds glamorous — until someone mentions the words tax residency.
The problem nobody warns you about
Most countries decide whether you're a tax resident based on how many days you spend on their soil in a financial or calendar year. Cross a threshold — 182 days in India, 183 days in many other countries — and your entire tax situation can change. Where you pay tax, on what income, and at what rate can all hinge on a simple day count.
The scary part? Almost nobody tracks this properly. Frequent travellers, expats, and remote workers often find out they've tripped a residency threshold only after the fact, when fixing it is expensive.
Spreadsheets weren't enough
Like most people, I started with a spreadsheet. Flight dates in one column, countries in another, a running tally per tax year. It worked for about two months. Then a trip slipped through, a layover got counted wrong, and I lost confidence in the numbers entirely. A tool that you can't trust is worse than no tool at all.
I looked around for something purpose-built and found either clunky enterprise software aimed at corporate mobility teams or apps that wanted my entire life story before showing me a single feature. Nothing felt like it was built for a person like me.
Building BorderBook
So I built it myself. BorderBook is a one-stop platform to track residency days for tax considerations. You log your travel — countries and dates — and it automatically keeps a running count of your days in each jurisdiction, mapped against the residency thresholds that matter. No spreadsheets, no mental math, no nasty surprises at the end of the financial year.
I kept it deliberately small. It does one job and tries to do it well: help frequent travellers and expats stay compliant without turning record-keeping into a second job.
What I learned
Building a tool for yourself first is the best product advice I've ever followed. Every feature in BorderBook exists because I needed it on an actual trip. And shipping something small but real taught me more about product thinking than any growth framework I've used at work.
Try it and tell me what's missing
If you travel often, live across countries, or work remotely from different places, I'd genuinely love for you to try it. Try BorderBook here — and if something's confusing, broken, or missing, tell me. Your feedback directly shapes what I build next. You can reach me on LinkedIn anytime.