My DS shares a uni flat (London) with his friend. They get on well and I'd say are good mates.
They're 7 months into the lease and every single month has required nagging by DS to the flatmate for the rent money. They are joint and severally liable, and DS is the 'head tenant' so he is the one who has to transfer the money every month.
Every month he gets a different excuse as to why the rent is late. It ranges from, oh my bank won't transfer on a bank holiday, to my parents are away with work, my dad forgot to transfer me, I've spent too much so I can give you 80% now and the other 20% in two days time.
DS has been very clear that this needs to stop, and they've had several frank conversations about it. All of which lead to profuse apologies from the (frankly disorganised) flatmate.
The flatmate is now almost two weeks late paying the rent. It seems to be getting worse every time. The flatmate comes from a wealthy family (his dad was recently in a news article where it detailed that he'd made several million pounds in the last year--financier)
DS is on a tight budget so the £1000 rent money missing for parts of every month is stressful and worrying to him.
Sorry first posted this in money, but realised it would be better under property