I and my partner have a joint account and i am ringing the company’s to-do the transfer my direct debit over to the joint account by it is coming back saying it’s not recognised even though we have the correct sort code and account number.
rang customer services and they don’t know on Monzo either and I’m awaiting the joint accounts team.
Some companies with really out dated systems don’t recognise the Monzo sort code. It’s getting much rarer these days but thankfully Monzo have a dedicated team to help.
You can email acceptance@monzo.com 
Out of interest what company is it?
Edit Just re-read your message, are you saying all companies don’t recognise Monzo or just the one?
yeah all of them are not recognising the joint account but they are with my personal monzo account
That’s crazy. I don’t know what the issue is then 
I was under the impression that they just check sort codes and since it’s the same sort code for both joint and personal accounts both should be fine.
Hopefully you hear back from Monzo soon and get to the bottom of it 
FYI: I have a joint account and all our bills come from there with no issues.
That sounds like it might be a Monzo problem then, do they check Sort (static) and Account Number in direct debit systems? Might be the Account Number is ‘faulty’ somehow?
We have several Direct Debits coming from our Joint Account with no issues at all (all household stuff).
Hope you get it sorted ASAP!
May be obvious but you are giving the sort code as 04-00-04 and not 04-00-40? Also, would you mind sharing some if the companies?
my sort code for my joint account is 04-00-04