Most solo founders do not fail because they cannot sell. They fail because they cannot see cash.

Invoices go out. Clients pay late. Software bills hit on the 3rd. You feel busy, so you assume the money is there. Then a tax quarter arrives and it is not.

I built a habit that takes twelve minutes every Friday:

1. What actually landed in the account this week (not what was invoiced).

2. What is still unpaid, and who is 14+ days late.

3. What leaves the account in the next 14 days.

4. What is left after that — that is the only number you may pay yourself from.

If step 4 is negative, you do not "figure it out later." You send the late invoices that day, or you cut a bill.

The Solo Founder's Billing & Cash-Flow Kit is the sheet, the five admin templates, and a one-page guide that makes this Friday check automatic. One purchase. No subscription. No bookkeeper required.

If you are still tracking money in your head, start there.