Every quarter I have to do the annoying task of doing my VAT return. I have to go through all the payments I have made for the quarter and get all invoices manually, which is a hassle as I have to log into all sorts of dashboards to download them. And as it is only each quarter, I keep forgetting where to get some of them.

So I figured Claude Cowork could help me fix this by asking it to pull the last quarter’s invoices from my subscriptions.

I started out by just asking Claude Cowork to handle this in a very basic way with a simple prompt. Then Claude asked me to set some permissions because it needed computer use. So I gave them and had to set the permissions in macOS.

Let’s see if it gets something done that is worthwhile and makes my life actually easier. I asked Claude to download the OpenAI invoices of the last quarter and send them to a custom email address my accounting software uses to import an invoice.

It started by asking me whether this should be a scheduled task, which sounded good because this is something that comes back every quarter. And so it makes sense to have this automated and scheduled. The funny thing is that the scheduling was done before it actually worked correctly.

Before we started I set the model to Sonnet 4.6 instead of the newly released Opus 4.7, because I knew computer use was going to be a drain for my usage limits. And boy, was I confirmed in my beliefs that this would become a problem. After 20 minutes of Claude going around in circles I checked my usage limits, and I was already through half of my 5 hour usage limit. Ugh. Here we go again.

About 5 minutes later Claude asked me to download the 3 invoices manually from the OpenAI website. Mission failed. A second run went in loops. Only when I pushed Claude to think harder did it finally manage to download the invoices and send them to the email address. A win, technically.

It took me an hour. Manually: two minutes.

Key Insight

I kept going, even though I spent way too much time already. I could have stopped after 20 minutes when I checked my usage. But I didn’t. So I spent another 40 minutes making a small loss of time into a big loss.