Real-life MMD: Should I sneakily keep some of ex's deposit for cleaning?

Not much of a dilemma here, you're already decided to give her £300.

You are 'tempted' to keep her £100 not because of the cleaning issue, but because she thinks it was a different amount.`

Your options are :
You £500, her £300 - in which case your cleaning bill was £200,:eek: not a pretty sight.
You £450, her £350 - a more reasonable £100 cleaning bill (can I clean for you please, next time)
You £400, her £400 - you only had to clear up after one person, after all, yourself.

She many not have forgotten. What if she's just testing to see how honest and honourable you are????

Your mess - your cleaning responsibility !

If its been left to built up over time - your problem !

But money that's not yours - hand it over please otherwise it's theft.

If your ex-partner is such that the amount owing has been forgotten, and that cleaning up after vacating a home is considered someone else's responsibility, then by all means keep the £100 as payment for what you did.

Having rented a number of houses I know that doing a clean when you've completely moved out is NOT the same as just generally keeping the house clean. Potentially washing carpets (depending on your lease), the windows, the whole of the kitchen including inside of all cupboards is not a quick or easy job.

If you took out the tenncy jointly then to me ALL responsibility is joint, including the final clean. Even if your ex moved out some time before the lease ended/you did the final clean is still joint, unless you've lived in a pig sty since she moved out then as others have said why she should clean your mess up.

I've been in a similar situation, deposit paid 50/50 but ex with very little stuff moved out and went back to his parents before I finally moved out to another house (couldnt and didnt want to pay 2 lots of rent for more time than necessary). I went back and spent the required time doing the move out clean before returning keys to agents before end of tennacy so carpet cleaners could collect to do before the end of our tennancy.

The agents (the most picky I've ever rented from) called me to say some things not satisfactorily clean so i went back (during working hours so time off work!) to collect keys and do jobs they'd mentioned. They then called AGAIN with different list which needed to be done in next 2 days before lease ended - I said I suggest you contact Mr x (my ex). He then called me saying he wasn't around so couldn't I go back to do it - promptly told him I'd already done full clean and been back once so no. Agency charged us £70 for the time they say they had to pay someone to clean final bits but as they deducted from deposit money at least I only had to pay half of it!

If I'd had any chance to effectively charge my ex for my time and energy spent would I, oh yes, certainly his half of, seeing as he knew he had to do it but decided not to.

As for keeping money undeclared, no I don't think I would. Plus are you honestly saying you value the time/energy you spent cleaning at £200 for her half to be worth £100?

I think I'd give her £350, telling her deposit was £400 each but seeing as she didnt put any time, effort or materials to cleaning the place so you could get full deposit back you think it's only fair. That way she's got more than she was expecting so will probably be happy, you've had some contribution from her towards her responsibility to cleaning up and there's nothing sneaky about it!