In my experience, providing a return address has always resulted in the letter being rejected and returned.
My best guess is that the sorting office camera’s scan the envelope, detect a full address, check for the correct postage, it fails + is rejected.
I’ve sent about 8 cheques in 2-3 years. I had one particular cheque that was high value, so of course listed a return address. It was rejected, and failed a further five (5!!) times, all with fresh evelopes before I decided to try it without the return address. It arrived safely the first time I excluded the return address.
Pretty sure I heard somewhere that if an item of Royal Mail post gets lost, it goes to the lost post centre in Belfast, and if there isn’t a return address on the outside they open it up and check if there’s a return address on the inside first before declaring it lost. So if you are concerned about it getting lost, you could instead put a slip of paper in the envelope with ‘return address’ and your address on it, and it would ultimately have the same result. Or possibly even write your name and address on the back of the cheque? I don’t think that would affect Monzo cashing it in? Pretty sure you can write anything on the back and it doesn’t matter, but could be wrong
That would be my suggestion. If I was sending a cheque I would have an A4 ‘letter’ sheet wrapped around it in the envelope anyway, as would be worried about a cheque on its own being seen through the envelope and pinched. So I’d have the return address on that sheet.
It does sound like it’s an automated sorting fail. As the machines don’t know which side of the envelope is the front, they’re going to identify the side with the longer address as the ‘front’ and frank that, aren’t they?
Just realised though, what happened to you doesn’t make the above bad advice. Because you wrote something else on the envelope.
Monzo desperately need cheque imaging… I had to post a high value cheque a couple of months back and sent it to Monzo tracked. But that cost me money. Which is annoying. The irony is that most ‘legacy banks’ are less legacy and have already implemented cheque imaging…
“Freepost Name”, like Freepost Monzo, is valid, but from your picture it looks like you put a return address on the front? The mail centre machines try to locate a full address on the front of the envelope, so if they find one then they’ll sort it straight back to you. Return address goes on the back.
(at one time I led the team that provides the software to do Royal Mail’s letters sortation)
They do know which is the front, but they’re trying to do something called address block location (ABL) to pick the area that looks most like an address, before then using OCR and other techniques to figure out where to sort it to. In this case the ABL picks up the return address as being more likely to be the destination than just Freepost Monzo.
Might sound a strange choice, but if you think how busy junkmail or magazines can be, ABL is quite a hard problem and it occasionally goes wrong. Generally it then goes for manual keying, but on this occasion i’m guessing it believed it had a full-depth sort.
It’s a harder problem than it might seem - we get very close to 100% right for on-spec machine print (like your bank statements) but junkmail, handwritten letters (especially christmas cards), and polywrap magazines and catalogues are hard. Throughput’s high too, each machine will do more than ten letters a second, and we have to OCR all of them in real time. Of course, we only notice the ones that go a bit wrong