What I’m trying to understand is why the decision to move from billable calls to retainer model? Was it only the ease of invoicing or were there other factors ?
Also, “Dismissing the use of simple tools or feeling like everything has to be automated and perfect is a recipe for disaster”
“Automate only once you have a repeatable process that has low to no variation in output”
Love these two advice! Applicable to almost every business
I never invoiced clients immediately for a service, everything was based on written contracts, and no I wouldn't use an app like that ever for a professional client. Businesses have a typical cadence of weekly or monthly invoicing, doing anything more rapid is less a professional service and more a buy here/pay here credit card mentality. There is nothing wrong with that more immediate model mind you, just isn't the same thing as a contractual service between businesses.
If my goal was the immediate model you are discussing, I'd require a payment up front before the call/service was delivered. e.g. you pay for the call, then are connected and the payment covers up to a certain time period with no refunds, more time more money. Or alternatively, the payment details are taken up front but the time is tracked and the payment is completed once the call is done. But that isn't a B2B transaction, that's more a consumer model, again, nothing wrong with it, just different strokes.
There are tools that can help make time tracking easier, I used to have my teams use an app (IIRC HoursTracker, or TimeTracker something like that) that let us setup projects, roles and rates and people could track their time in it. The app was inexpensive, like $5-6/per user and at the end of each week they would just use the app to send us their time. It would put it in a csv file and email to admin so we could then add the details to the invoices for clients. We didn't really use the rates section of the app, but the csv could've easily been converted into an excel invoice with a tiny bit of script. We did use the csv to import the time into our accounting tools too, made it nice to eliminate data entry mistakes.
I didn't do so much freelancing as I built consulting groups where we did software/hardware design/development, marketing and go to market planning for clients across numerous industries. So billable video calls and conference calls for strategy talks or status check ins were common. For the vast majority of clients we also stopped billing hourly all together and did weekly flat rates or monthly retainer agreements which made invoicing easier, but we still tracked time using the app.
Just a comment, not necessarily your issue, but something I council new freelancers and startups on quite often. A lot of business is done in excel and by hand, this is not bad, it actually forces vigilance and properly used is more powerful than a full blown ERP sometimes. Dismissing the use of simple tools or feeling like everything has to be automated and perfect is a recipe for disaster IMO, automate only once you have a repeatable process that has low to no variation in output etc.