Gym Invoicing and Billing App: Memberships, PT Packs and Failed Payments

Gym invoicing is mostly recurring: monthly or annual memberships, with personal training packs, joining fees and the odd corporate deal on top. Mythex builds a billing app from a description of how you charge, with member records, invoices, statuses and a list of failed payments to chase, and publishes it with a real database.

Who it's for

Gyms, studios and personal trainers who bill from a spreadsheet, a card terminal and a stack of standing orders, and lose track of who has paid for which PT pack. It also suits gyms that sell corporate memberships to local employers.

What you can build

Monthly and annual membership invoices with the tier and term
Joining fees on the first invoice only
PT packs of 5 or 10 sessions billed separately from membership
A failed payment list with days overdue and member status
Corporate memberships billed to the employer each month
Pro-rated invoices when a member changes tier mid-month

What gym billing has to handle

Memberships bill on a cycle, PT packs bill once and count down, and a joining fee appears once. Keep them as separate products so a member's PT pack never disappears into their membership line. Freezes should pause billing under your rules. Corporate deals need one invoice to the employer with a list of members, and members who change tier mid-month need a pro-rated line that does not confuse anyone.

Membership, PT and joining fee as separate items
Freezes that pause billing
Employer invoices with a member list
Pro-rating on tier changes

Chase failed payments in days, not months

Most failed membership payments are expired cards, not people leaving. A list of failed payments with how many days overdue, and a polite message with a link to update the card, recovers most of them. A member unpaid for two months is much harder to win back.

Mistakes to avoid

Do not invoice PT sessions one at a time when members buy packs; it creates a mess of tiny invoices. Do not let staff change prices on individual invoices without a note. And check the tax rules where you operate for memberships and personal training before setting rates.

What to set up first

Enter your tiers and PT packs as products with prices, import members with their tier and billing date, and connect a payment provider that supports subscriptions. Run the first month in parallel with your current method, then switch.

A prompt to start from

Build an invoicing app for my gym. Products: three membership tiers billed monthly or annually, a one-off joining fee on the first invoice, and PT packs of 5 or 10 sessions. Members on a freeze are not billed. Employers can have a corporate account with one monthly invoice listing their staff members. Show a list of failed or overdue payments with days overdue and a button to email a card update link.

Questions

Can it take recurring membership payments?

Yes, after you connect a subscription-capable provider such as Stripe under the gym's own account. Each invoice and its status is kept in the app.

Can I sell PT packs separately?

Yes. PT packs can be their own product, billed once, with sessions counted down as they are used.

Can I bill an employer for staff memberships?

Yes. A corporate account can receive one invoice per month listing the members it covers.

Does it handle tax?

It can add tax lines at the rates you set. Check with your accountant which rates apply to memberships and training where you operate.

Is it free?

You can build billing on Free without a card. Pro adds a custom domain and extra credits for $25 a month.

Templates to start from

Fintech Payments Site Template — Tiered pricing, blog, animations
AI Trip Planner Template — Chat itineraries with billing-ready UI
Invoice Generator Template — Canvas invoicing with PDF export
Cloud Storage SaaS Template — Marketing site, billing UI, and 2FA
Trade Publication Template — Research reports, jobs, memberships