Painting ceilings that are very mouldy, what to do?

Good morning

I have the task of painting a bedroom & bathroom ceiling on the second floor of a small one bed house. The white ceilings have dark black mould around the edges, about a foot wide in places & mostly by the windows. I basically want to get the ceilings back to pristine white. I think the tenants are always showering & tumble drying with the windows shut I'll tell them to have good ventilation in future!
Could someone help me with what I need to do & what paint products would be best for me please.

Thank you!
Boons

Lightly rub it down, paint with pva solution, let it dry then re paint.
But Im only a DIYer.

Scrub the affected part of the ceiling well with ½ bucket of hot water into which you’ve added a squirt of washing up liquid & around five tablespoons full of white vinegar & repeat if necessary; use one of those green kitchen scourers. Leave to dry thoroughly & re-paint preferably with an anti fungicidal bathroom emulsion; I wouldn’t use PVA, the paint won’t cover it very well & it could peel off when it all gets damp again.

As you say, make sure they ventilate the bathroom when bathing & their tumble dryer must either be externally vented or the condensing type; & tell them if it happens again, you’ll charge them the cost of re-decorating! If you can, get fans installed in the bathroom/utility (both required by current building regs. anyway) linked to the light circuits which they can't turn off; make sure you use a Part P spark to install them though.

I used bleach to kill black mould around some windows in my house (left by previous owners...). I left it to dry out for a few weeks during the Summer and then simply re-painted with normal emulsion. It hasn't returned - I obviously ventilate better than the old owners! If I were you, I'd install a fan in the bathroom - although this of course means your tenants would have to remember to turn it on/off.

Great stuff, thanks guys

Scrub a solution of four parts water to one bleach over the area and leave overnight...wash off and give the ceiling a couple of coats of emulsion..

DONT use PVA..it isnt a cure all.

Brilliant thank you!