Short answer. Personal trainer invoicing software lets you raise an invoice for a session, a package or a custom amount, email it with a card payment link, and see who has paid and who is overdue. FitDesk does that as part of its personal trainer software for UK trainers, next to bookings and client records. No monthly fee. 0.7% on card and Direct Debit payments through FitDesk, minimum 1p. Stripe's own fees still apply. Cash has no FitDesk fee. FitDesk plans to stay free for trainers. Create your FitDesk account
What is personal trainer invoicing software?
It is a tool that turns the sessions and packages you sell into invoices your clients can pay, then keeps the record. For a personal trainer it should:
- Raise an invoice for a single session, a package of sessions or a custom amount.
- Email the invoice to the client with a way to pay by card.
- Show which invoices are paid, unpaid or overdue.
- Let you resend an invoice, or send several at once at the start of a month.
- Record cash payments, so every payment sits against the right client.
- Keep invoices next to bookings, so you can see what each client owes for the sessions they had.
A spreadsheet and a general invoicing app can do part of this. Invoicing built into your PT software saves you copying client names, dates and session prices from one system to another.
What must a UK personal trainer invoice include?
GOV.UK lists what an invoice must include. In short:
- A unique invoice number.
- Your name or business name, address and contact details.
- The name and address of the client you are invoicing.
- A clear description of what you are charging for, such as "4 personal training sessions".
- The date the service was provided and the date of the invoice.
- The amount charged, any VAT if you are VAT registered, and the total owed.
If you are a sole trader, the invoice must also show your own name and any business name you use. If you trade through a limited company, use the full company name as it appears on your certificate of incorporation. Only use a VAT invoice if you are VAT registered. Keep your records: GOV.UK says self employed people must keep records for at least 5 years after the 31 January submission deadline of the relevant tax year.
How does invoicing work in FitDesk?
Raising and sending invoices
Connect your own Stripe account in FitDesk. Then raise an invoice for a session, a package or a custom amount, and FitDesk emails the client a payment link so they can pay by card from their phone or computer. You can resend an invoice, and send invoices in bulk when several clients are due at once.
Seeing who owes you
Invoices, card payments and recorded cash payments sit against each client, next to their bookings. Overdue invoices are marked, and your dashboard shows who owes you money, so you can follow up before it builds up. The FitDesk AI assistant can draft a polite reminder message for you to check and send.
Cash payments
If a client pays you in cash, record it in FitDesk so your records stay complete. Cash has no FitDesk fee.
How do you bill clients every month?
FitDesk monthly plans let a client pay you a set amount each month for a set number of sessions, by card or Direct Debit. Stripe takes each payment on your own Stripe account. For regular clients you can also:
- Send a monthly invoice with a card payment link, or several at once in bulk at the start of the month.
- Sell a package of sessions. FitDesk keeps track of how many sessions each client has left.
You can pair a monthly plan or a package with repeat weekly bookings, so the diary and the money stay in step. Our personal trainer payment system guide explains the trade offs.
What does FitDesk invoicing cost?
Invoicing is included. There is no monthly fee and no client cap, and no card is needed to sign up. 0.7% on card and Direct Debit payments through FitDesk, minimum 1p. Stripe's own fees still apply. Cash has no FitDesk fee. FitDesk plans to stay free for trainers.
Card payments settle into your own Stripe account and then your bank on Stripe's payout schedule. FitDesk does not hold your money.
Frequently asked questions
What is personal trainer invoicing software?
It is software that turns the sessions and packages you sell into invoices clients can pay. It raises the invoice, emails it with a payment link, shows what is paid or overdue and keeps the record. In FitDesk, invoices sit next to each client's bookings, so billing and the diary stay in one place.
Can I send invoices to clients with FitDesk?
Yes. Raise an invoice for a session, a package or a custom amount, and FitDesk emails the client a payment link so they can pay by card through Stripe. You can resend an invoice, send invoices in bulk, and see overdue invoices marked against each client in your account.
What should a personal trainer invoice include in the UK?
GOV.UK says an invoice needs a unique number, your name or business name and contact details, the client's name and address, a description of the service, the supply date, the invoice date, the amount and the total owed. Sole traders also show their own name. Add VAT only if you are VAT registered.
Can FitDesk take monthly payments by direct debit?
Yes, with FitDesk monthly plans. Stripe processes the Direct Debit on your own Stripe account, and clients can pay by card instead. FitDesk takes 0.7% of each payment (minimum 1p) from your takings, and Stripe's own fees still apply. The Direct Debit Guarantee is given by the client's bank, not by FitDesk.
How do clients pay a FitDesk invoice?
Clients open the invoice email and pay by card through the payment link. The money goes to your own connected Stripe account and then to your bank on Stripe's payout schedule. If a client pays you in cash instead, record the payment in FitDesk so your records stay complete.
How much does FitDesk charge for invoicing?
Invoicing is included with no monthly fee and no client cap. 0.7% on card and Direct Debit payments through FitDesk, minimum 1p. Stripe's own fees still apply. Cash has no FitDesk fee. FitDesk plans to stay free for trainers. Payments are cash, Stripe card or Direct Debit through FitDesk monthly plans. FitDesk plans to stay free for trainers.
Sources
- GOV.UK, Invoicing and taking payment from customers: what invoices must include, read 3 November 2026.
- GOV.UK, Business records if you're self employed: how long to keep your records, read 3 November 2026.
Related guides
- Personal trainer software UK
- Personal trainer payment system
- Stripe for personal trainers
- How to take card payments as a personal trainer
- Personal trainer scheduling software UK
- Self employed personal trainer UK guide
Try FitDesk
No monthly fee. 0.7% on card and Direct Debit payments through FitDesk, minimum 1p. Stripe's own fees still apply. Cash has no FitDesk fee. FitDesk plans to stay free for trainers. Create your FitDesk account