Welcome to the community @Alexpg.
You can achieve this with IFTTT.
If you’re not interested in setting the applets up for yourself then you can use mine but these are unofficial unsupported etc.:
If you want to set up your own applets so you have full control then you’ll sign up as a “developer” on https://platform.ifttt.com/, create your own applet with the following:
- Trigger: Any card purchase above an amount
- Action: Move money into a pot
Once you’ve added both of those then in between them click “Add filter code” and you can use this example code below to work out a percentage of the roundup:
var spendVal = parseFloat(Monzo.cardPurchaseAboveAmount.AmountInAccountCurrency)
// Check whether the transaction would have resulted in a round up
var rem = ( spendVal % 1 )
if ( rem === 0 )
{
// Purchases that are integers do not round up
Monzo.potDeposit.skip();
} else {
// Set the pot deposit as 70% of the spare change - amend "0.7" to change the percentage
var roundUp = ( 1 - rem ).toFixed(2)
var partRoundUp = (parseFloat(roundUp) * 0.7).toFixed(2)
Monzo.potDeposit.setAmount(partRoundUp);
}
You’ll need to create one applet for 70% and one for 30% and you’re good to go; any questions let me know or post them into the support thread.