Class Packs, Memberships and Sessions Used vs Owed: How a Melbourne PT Studio Bills

By the InvoiceFlow team — published 16 June 2026 — 10 minute read

Dani Kostas runs a small personal-training studio in Brunswick, an inner-northern Melbourne suburb where the warehouses have turned into cafés and the cafés are full of people who'd like to be a bit fitter. The studio is one converted garage with a rig, some kettlebells, a rower, and a whiteboard. On a busy day she and one other coach run back-to-back small-group classes and one-on-one sessions from six in the morning until eight at night. The training, she'll tell you, is the easy bit. She loves the training. What nearly broke her in the first year was the money — specifically, the question of who had paid for what, used how much of it, and still owed her anything.

Because a PT studio is not one business with one billing model. It is at least three. There are the people who buy a ten-class pack and draw it down over a month or two. There are the people on a monthly membership who pay the same amount on the same day forever. And there are the one-on-one clients she bills by actual time, where a "60-minute" session is sometimes 75 because someone needed the extra work. Three models, dozens of clients, and for a long time one increasingly chaotic notebook trying to hold all of it together.

Why a PT studio's billing gets messy so fast

The first thing to understand about a studio like Dani's is that almost nothing is "pay once and done." A single drop-in class is the only clean transaction in the building. Everything else carries state — a balance that changes over time, a commitment that recurs, an hour that hasn't been logged yet.

A class pack is the obvious trap. A client buys ten classes for AUD 280. That's not a sale, it's the opening balance of a relationship that plays out over weeks, ticking down by one every time they show up. If Dani can't see that balance at a glance, she either lets someone train on a pack that ran out three sessions ago — money she's giving away — or interrupts the warm-up to flip through a notebook, which makes a premium service feel like a corner shop.

Memberships have the opposite problem: they're so predictable they get forgotten. Twenty members each paying AUD 160 a month is the floor under the whole studio, AUD 3,200 that should land like clockwork. But "should" is doing a lot of work in that sentence. The month she issued every membership invoice by hand, she missed two entirely and only noticed when the bank balance came up short. Predictable income still has to actually be billed.

And the one-on-one work is the hardest of the three to capture, because the unit being sold is time, and time slips. A session runs long. If the only record is Dani's memory and a glance at the clock, some of that work simply never makes it onto an invoice. Unbilled time is the quietest way a service business bleeds.

Memberships: let the recurring schedule do the billing

Dani's memberships are the part she now never thinks about, because InvoiceFlow handles them with recurring schedules. A recurring schedule auto-generates an invoice on a cadence — monthly, in her case — with correct sequential numbering, so the documents never collide or skip a number.

She runs two membership tiers. Studio is unlimited small-group classes for a flat AUD 160 a month. Studio+ adds two one-on-one sessions a month and a small discount on extras, at AUD 290. For each member she sets up a monthly recurring schedule for the membership fee, attached to the right client. On the first of every month, the invoices generate themselves. She no longer "does the memberships" — they're done before she's poured her coffee.

This is the same mechanic any subscription or retainer business leans on, and it fits a membership exactly: the commitment recurs, so the invoice should too. The numbering stays sequential across all of them automatically, which matters at tax time when she hands everything to her accountant. The chore that used to eat the first morning of every month — remembering who's a member, what tier they're on, and issuing each invoice by hand — now happens whether she thinks about it or not.

A note on what InvoiceFlow is (and isn't)

Worth being clear, because the fitness-software world is full of overpromises. InvoiceFlow is not a payment processor and not a booking app. It creates the documents and tracks the money; it can display payment instructions on the invoice — bank details, a payment link, or a QR code — and the client pays through their own method. Dani then marks each invoice Paid or Partially Paid. For her that separation is a feature, not a gap: her bank stays her bank, her gym-floor booking stays wherever she keeps it, and the app stays the clean, single record of who owes what.

Class packs: the amount-due trick

The cleverest part of Dani's setup is how she handles prepaid class packs, and it leans on a feature most people associate with slow-paying clients rather than fitness: partial payments and amount due.

Here's the model. A client buys a ten-class pack for AUD 280 — twenty-eight dollars a class, a small discount on the drop-in rate. Dani issues a single invoice for the full AUD 280, the whole pack billed up front as one document. The client pays, and the invoice is marked Paid. Ordinary so far.

But Dani wanted that invoice to double as the ledger of classes used, and InvoiceFlow's partial-payment tracking gives her a clean mental model for it. The amount-due mechanic — where the app tracks a remaining balance against a total — maps perfectly onto a pack that draws down. She keeps a running view of what's been consumed against what was paid for, so at any moment she can answer the question every pack client eventually asks at the door: "How many do I have left?"

For clients who'd rather not drop AUD 280 in one hit, the same feature runs the other way. Someone commits to the ten-class pack but pays AUD 140 now and AUD 140 in a fortnight. Dani records the partial payment; the app tracks the AUD 140 still owed. The client starts training immediately, the balance is never in doubt, and there's no second spreadsheet shadowing the first. The remaining balance lives on the document itself.

Or split it into a plan

For her premium offering — a twelve-week transformation block aimed at people training for a specific event — Dani sometimes uses a split payment schedule instead. The total breaks into an installment plan, and the installment template renders the schedule right on the PDF, so the client sees exactly what's due and when. Same block of work, presented as a payment plan rather than one intimidating up-front number. Which option she offers depends on the client; the point is the app supports all three — paid in full, partial with a tracked balance, or a formal installment plan.

Member tiers: categories that mean something

Once you run two membership tiers and several pack types, your client list stops being a flat roll of names and becomes a set of relationships you need to see at a glance. Dani uses client categories for this, with parent categories and child sub-categories.

Her structure looks like this:

The categories aren't decoration; they're how she runs the studio. When she wants to nudge everyone on the Studio tier toward Studio+, she filters to that category. When she's launching a new early-morning strength block and wants to invite the right people, she looks at the relevant segment instead of scrolling her whole book. InvoiceFlow's advanced filters let her narrow the client list by these categories and attributes, and a dedicated client-groups screen is where she manages the whole structure. The parent-and-child shape means she can think broadly ("all members") or narrowly ("Studio+ specifically") without re-tagging anyone.

The "Drop-in" category does quiet, useful work too. It's her conversion pipeline. Every few weeks she filters to Drop-in, sees who's been in three or more times without committing to a pack or membership, and those are the people she has a friendly word with. The category turns a vague intention — "I should sign up more regulars" — into a specific, short list of names.

The time tracker: billing the work that slips

The piece that genuinely changed Dani's bottom line was the Time Tracker. For her one-on-one clients, the unit she sells is billable time, and time is exactly the thing that used to vanish between the session and the invoice.

Now she runs the timer on the studio phone. A session booked for 60 minutes that runs to 75 because a client needed extra mobility work is captured as 75 minutes, not rounded down to the booking out of vague guilt. When she invoices, that tracked time turns straight into invoice line items — the hours she actually worked, not the hours she half-remembers. It's the same workflow a consultant or a lawyer uses to bill by the hour, applied to a gym floor.

The effect over a month is not small. A studio doing dozens of one-on-one sessions, each quietly running five or ten minutes long, gives away hours of unbilled work it never sees. Tracking the time and converting it to line items closes that leak without Dani having to become the kind of person who watches the clock mid-session. The timer watches it for her.

A week in the studio

Picture the first of the month. Dani's recurring schedules fire, and every membership invoice generates itself with the next sequential number. Studio and Studio+ members get their invoices; she sends them by email with a payment link, and as payments land she marks each Paid. The floor under the studio's income is in place before a single class has run.

Tuesday, a pack client finishes the eighth class of her ten-class pack. Dani glances at the remaining balance on the pack invoice — two left — and mentions it as the client racks the bar: "Two more after today; want to roll into another pack?" The client, who had no idea she was nearly out, says yes on the spot. That conversation only happens because the number was visible.

Thursday evening she finishes a long one-on-one that ran fifteen minutes over; the timer was running, so the extra time is logged, and at the end of the week she turns the week's tracked one-on-one time into invoices, billing the real hours.

Saturday a new face — the kind who used to be a one-off drop-in — comes in for a third class and asks about "doing this properly." Dani offers the ten-class pack, takes an AUD 140 partial payment to start, records the balance, and re-categorises the client from Drop-in to Pack clients. A casual visitor just became a tracked, committed relationship.

Polishing the client-facing side

Because these documents go to clients paying a premium for personal attention, the invoices have to carry that. Dani uses one of the 12 built-in PDF templates — the modern one suits the studio's brand — with her logo placed automatically by the two-logo system, square mark on the narrow layouts and the wide wordmark across the header. She bills everything in Australian dollars with correct formatting, and where GST applies she sets the tax treatment once so every invoice handles it the same way. A membership is a long relationship and a class pack is weeks of contact; every document along the way is a small touchpoint, and they add up to how professional the whole thing feels.

What Dani would tell another studio owner

  1. Accept that you run three billing models, not one. Packs, memberships, and time-based work behave nothing alike. Stop forcing them through one notebook and give each the right tool.
  2. Bill memberships on a recurring schedule. A recurring commitment deserves a recurring invoice. Set it once per member and let the first of the month take care of itself — predictable income still has to actually be billed.
  3. Treat a class pack as a balance, not a one-time sale. Track classes used against classes paid for, so you can always answer "how many do I have left?" — and turn that answer into a renewal at the door.
  4. Track your one-on-one time and turn it into line items. The five and ten minutes that sessions run long are real work. Capture them or keep giving them away.
  5. Categorise clients by what they've actually bought. Tiers and pack types as categories turn a flat name list into a tool — for upgrades, new offerings, and converting drop-ins into regulars.

Dani still coaches the same classes in the same converted garage, with the same kettlebells and the same whiteboard. What changed is the structure underneath. On the first of the month, a known set of memberships bills itself. Through the month, every pack has a visible balance that prompts its own renewal, and every long session gets captured instead of forgotten. Her client list is no longer a list — it's a map of who's committed, who's drawing down a pack, whose time hasn't been billed yet, and who's one good conversation away from becoming a regular.