Hi Judi,
I can't add any experience with card readers from a Quaker Meeting House, but I can add some from Holy Trinity PCC Bradford on Avon (Church of England) where I work in a second mini-employment as bookkeeper.
Holy Trinity uses SumUp and has a number of small card readers as well as a big chunky Payaz machine. The card readers are used for collections at Sunday Services, payments for refreshments, and donations at special events. SumUp charges 1.1% for each transaction, not sure how Holy Trinity managed to get such a low rate. The chunky Payaz machine sits near the entrance to Holy Trinity, a mediavel church that is open every day for touristy and other visitors and gets quite a bit of footfall thanks to being opposite the much-visited little Saxon Church. The Payaz machine cost over 300 pounds and had to be sent off for repair at least once during the warranty period. It also went down recently for a little while after we had made changes to the wifi setup, but this got sorted fairly quickly.
In terms of bookkeeping: I get daily payout reports by e-mail showing day and time of payment, so when I want to allocate payments to 'fundraising community events' rather than 'donations', it's fairly straightforward to see from the list which payments were made when. In principle, you can also set the system to temporarily allocate it to another kind of income, but changing the settings requires 2-step identification, and as the details are my e-mail and mobile number and I'm not usually there, this is a bit of a non-starter.
The Payaz machine also allows people to gift-aid their donations through the 'Give a little' scheme. I can download a list of gift-aided donations with details of donors from the 'Give a little' website and export it in an HMRC-friendly format. However, as I have to amalgamate this with my spreadsheet of other gift-aided donations (mostly from people paying by standing order), it does become very fiddly and quite time-consuming for relatively little additional income. Still worth the effort though, just a bit tedious.
It's hard to tell whether or not the card readers and Payaz machine have resulted in an increase of giving. They certainly have made their money back many times over by now in terms of what's gone through them.
Best wishes,
Klaus Huber
Resident Warden, Bradford on Avon (and writing this time from experience as Holy Trinity Bradford on Avon PCC bookkeeper)