Ask for a deposit

A small deposit for anything that holds a slot, and names out of a hat in place of a race when slots are scarce.

Tidewater Bakery is invented for this post. The names, orders, times and figures are made up.

The deposit

A £5 deposit holds your order. It comes off the price when you collect.

Cancel up to 48 hours before and we refund it.

The customer pays it when they confirm. Once it is paid, the slot is theirs.

What happens	The deposit
An assistant asks three times and nobody confirms	Nothing is paid
An assistant asks three times and the customer confirms one	£5 is paid, once
The customer collects the cake	The £5 comes off the price
The customer cancels 48 hours or more before	The £5 is refunded
The customer cancels later, or does not collect	The bakery keeps the £5

The bakery releases 12 Christmas cake slots on 1 November.

Time	What happens
09:00:00	slots open
09:00:01	nine taken by assistants, each submitting the moment it opened
09:00:40	the first person finishes typing; three slots left

Time	What happens
09:00 to 09:10	anyone can submit; one request per mobile number
09:10	twelve are picked at random
09:11	each winner gets a text with a link to pay the deposit

One request for a Christmas cake slot, seen from each side.

Before 1 November

The ordering page says 12 Christmas cake slots open at 09:00 on 1 November for ten minutes, names are picked at random, and a £5 deposit is due if you are picked.
09:00 to 09:10

Priya's assistant fills in the form with her name, her mobile number and the cake. The page says she is in the hat and will get a text either way.
09:10

Nothing to do.
09:11

Priya gets a text.

Tidewater Bakery: you have a Christmas cake slot. Pay the £5 deposit by 1pm today to keep it: tidewater.example/pay/7f3k
10:24

She follows the link. The page shows the cake, the collection date and the refund rule. She pays £5 and the slot is hers.
13:00

Nothing changes for Priya.
Collection day

She collects the cake and pays £37: the £42 price less the £5.

Before 1 November

Sets the 12 slots, the ten minutes and the £5 deposit.
09:00 to 09:10

24 requests arrive. A second request from the same mobile number is refused.
09:10

The site picks 12 of the 24 names at random and keeps the other 12 in the order picked, as reserves.
09:11

12 texts go out with a link to pay. The link checks the number: a made-up number cannot pay. The other 12 get a text with their place on the reserve list.
10:24

Priya's row changes to Paid 10:24.
13:00

10 of the 12 have paid. The 2 unpaid slots go to the first 2 reserves, who have until 18:00 today to pay. A reserve who has not paid by then is cancelled.
Collection day

Takes the £37. Had she not come, the bakery would keep the £5.