In most cases, your wallet pays what it can and you pay the rest by card, Apple Pay or Google Pay. Apply the wallet at checkout, then tap Continue to pay the rest.
When the wallet must cover everything
For these bookings, the wallet can only be used if it covers the full amount reserved:
A court booking where you're the lead booker and chose Pay your part.
Booking a league match as the lead booker.
Signing up a team for a league round.
If your balance is too low, the wallet is greyed out. See "Why is my club wallet greyed out at checkout?".
Good to know
For matches and private coaching where players pay their part, the wallet only needs to cover your own share.
Some wallets can't pay for extras such as racket hire. The extras then go on your card.
The technology fee, if there is one, is charged on the card part.