If you wanted to send me a monetary tip for my excellent Mastodon posts, which platform would you prefer to use?

@Edent @duncanlock Pretty sure there would be a merchant fee and the shop just ate it

@davidgerard @Edent @duncanlock yes. Using cards (even non-credit cards) costs the seller money.

@davidgerard @duncanlock @tante
Not really. In the UK, I pay a fixed % for tap-to-pay card transactions.

SumUp charge as little as 0.99% whether you're charging £1 or £500. My corner shop prefers that I pay by card for a chocolate bar rather than a £20 note.

@davidgerard @Edent @duncanlock Yes, the shop will have paid the transaction fee for this and it will have been a fairly large proportion of the payment.

Not as large in the UK as in the USA, but still a flat fee per transaction plus a percentage of the payment amount.

The payment providers that offer simple percentage pricing (eg. Square at 1.75% and SumUp at 1.69%) are able to do so because they insist on a minimum transaction amount of £1.

@Edent @davidgerard @duncanlock @tante SumUp's minimum payment amount in the UK is £1.

Their fees are rounded to a whole number of pennies per transaction using Banker's rounding (Round Half to Even).

@Edent Monzo are not bad for this.

e.g. https://pay.revk.uk

@Edent the internet would be a very different place if we could replace ads with micropayments

@revk @Edent Does this count as a messaging service? For a fee I can send you a message.

@dan @Edent When the whole OSA crap came in, this was pondered... I do not know.

@revk @Edent I am not spending £1 per message to find out.

@davidgerard @duncanlock @tante @steve ah, I misread their developer documentation.
I don't know which merchant my greengrocer uses, but they're able to charge less than a quid.

Of course, that's card-present. Looks like online payments still have a fixed fee overhead.

Thanks!

@dan @Edent By, for example, monzo to monzo, allows utf8 messages even on 1p transaction, and no fee.

@revk @dan
I've seen people sending messages over banking
https://shkspr.mobi/blog/2020/05/to-get-my-attention-pay-me/

@Edent The "traditional" card terminal providers like Barclaycard, Dojo, Worldpay and so on will have fee structures that incorporate a fixed "authorisation fee" and then a percentage of the payment which are likely to be different for each class of card (matrix of credit, debit, domestic, international, special case for Amex); they will happily process transactions that cost the merchant more than the transaction amount. They tend to pay out gross daily and then invoice fees monthly.

@Edent SumUp and Square pay out net daily. Stripe is the worst of both worlds; they pay out net daily but do have a flat fee plus percentage fee structure so it's possible for a small transaction to be completely eaten by fees.

(That's why, although Stripe have the best designed API for integration with POS systems, I don't support them in my POS system yet!)

@revk @Edent My problem with "open forms" like that is the possible abuse factor. I have heard of PayPal and UK bank accounts being frozen for silly messages such as "For drugs".

@Edent the only two I've actually used - because when I looked into them they didn't have some aspect that bothered me - are LiberaPay and Kofi.

@dan you can always bounce £1 between each other as a way to send a message

@revk @Edent

@steve @Edent @duncanlock yeah, lotta corner shops round here still say minimum £5. Even the ones that don't, i keep coins in my pocket so i can buy a drink or whatever without their share being eaten in card fees.

@Edent I have the app installed and played with the demo provider.
It is not widely supported yet but there are some places were it is used: https://www.taler.net/de/news/2025-04.html