Where Your Change Goes Now: A Guide to Marii Cards

You pay with a five, the bill is four dollars thirty, and the cashier looks at the till and then at the jar of sweets. You know the rest. It happens a few times a week, wherever you shop, and it adds up to real money that never comes back.

Marii Cards changes where that seventy cents goes. This is what happens, step by step, the first time a shop on Marii offers to keep your change.

1. The cashier saves it as credit

Instead of a sweet, the cashier asks for your phone number and saves the seventy cents as credit on a card in the shop's name. It takes three taps at their till. You may be handed a physical Marii card with the shop's name on it, or you may just give your number. Either works.

Before you have left the counter, your phone gets a text: how much was saved, at which shop, and what your credit there is now. That text arrives whether or not you have the app. It is your receipt.

2. The app shows you every shop in one place

Download Marii Cards from the App Store or Google Play and sign in with the number the till already has for you. There is no password and nothing to fill in. Each shop that has saved change for you appears as its own card, in that shop's name and colour, with its own activity underneath. Credit is never pooled. The butcher's seventy cents stays with the butcher.

3. You spend it with one code

Next time you are at that shop, open the app and show your pay code. It is one code for every shop on Marii, it changes every minute, and it works with no signal, so a queue never waits for your data. The cashier scans it and the credit comes off your bill.

No phone, flat battery, or no smartphone at all? Show your Marii card at the till and enter your four-digit PIN. The app is a convenience. It is never the key.

Why nobody else can spend it

Your credit is money you were owed, so it is protected the way money should be, by how the thing is built rather than by promises.

• Spending takes the code on your phone, or your card and your PIN. Your phone number alone can never spend.
• Your pay code is signed on your own phone. A shop can check it, but no shop, and not even Marii, can make one for you.
• Your PIN is never stored on a shop's device.
• Every time your card is used you get a text saying what was spent and what is left, with a number to call if it was not you.
• Lost your card? Report it in the app and it stops working at every till at once. Your credit stays exactly where it was, ready for a new card.

What else is in the app

Your other loyalty cards. The paper and plastic cards you already carry from other shops can live here too. Hold one up to the camera, the app reads its barcode and colour, and at the till you tap it and its code fills the screen. These cards hold no Marii credit, we have no part in those programmes, and they never leave your phone. Keep the plastic with you, because some tills cannot scan a screen.

Specials from shops you choose.Say yes at a shop's till and it can tell you about a weekend deal or new stock, as its own poster in the For you section. One switch per shop turns it off, and one switch turns off all of them. Off means off.

Stamp cards and cashback.If a shop runs a stamp card or cashback, your stamps sit on that shop's card next to your credit. Tap View rewards to see where you stand.

Questions people actually ask

More answers on the Marii Cards page →