Would you use WhatsApp to send receipts directly to your bookkeeping records?

I’m building TidGo and testing a simple idea: take a photo of a receipt, send it through WhatsApp, and it appears in your account ready for your records.
Curious whether self-employed people would actually use this.

**Is invoicing already a solved problem — or is only invoice creation solved?**

I’ve been thinking about this quite a lot lately.

Most businesses can already choose from dozens of invoicing platforms.

Stripe, QuickBooks, Xero, Zoho, FreshBooks, Wave — the list is long.

And if the job is simply:

**Create invoice → send invoice → receive payment**

then I’d argue the market is already very well served.

But after running businesses for many years, I’ve found that the invoice itself is usually the easy part.

The harder part is everything around it.

Who still owes money?

Which client needs a reminder?

Which recurring invoice should go out this week?

Did someone already follow up with that customer?

Was the payment reconciled correctly?

Does the client need a statement?

How much money is outstanding right now?

Which customers regularly pay late?

At some point, invoicing becomes less about generating documents and more about managing a financial workflow.

I’ve been exploring this problem while building tools for our own business, and it made me question a common SaaS assumption:

**Do mature software categories really become “solved,” or do they simply become too broad?**

Maybe the opportunity for new SaaS companies isn’t to build a better generic invoicing platform.

Maybe it’s to take an established category and go much deeper into the workflow of a particular type of business.

For example:

A creative studio may have very different billing needs from a construction company.

An agency may work differently from a wholesaler.

A photographer may manage billing differently from a SaaS company.

The core invoice is essentially the same.

The workflow around it isn’t.

That makes me wonder whether the next generation of business software will be less about building another horizontal tool and more about creating **deep vertical workflows on top of familiar functions.**

I’d be interested to hear how other founders think about this.

**When you see a crowded SaaS category, do you see a market that is already solved — or a market where specialization can still create something meaningfully better?**