British digital challenger bank Monzo has reinstated the much sought-after feature that allows users to top up their account from another debit card, or through Apple Pay and Android Pay.

However, the bank in its blog post noted that supporting this feature is ‘incredibly expensive’ for it to offer.

“Every time you top up from another debit card, Monzo has to pay processing fees, calculated at a percentage of the amount you top up. On average, this costs us around £24 per customer each year,” the post read.

The bank urged customers to only use the feature for last minute emergencies.

“It isn’t sustainable for us to keep covering the costs if everyone only uses top ups to add money to their Monzo accounts,” the post added.

The bank revealed that its product team is exploring ways in which these costs can be slashed.