Transfer apartment to sister

Who has been paying the management fees and landlord insurance since the last tenants moved out?

Can your sister afford them, plus the heating etc bills? (I'm not kidding, there can be some older people who cannot afford to run a house, even if bits gifted to them.)

How is letting someone live in your own house rent free a taxable gift? Everyone still living at home would be liable so.

OP she would be liable for gift tax so just leave the arrangement as is, why would she need to own it if she's no one to leave it to?

Why would it matter? There is still no obligation to charge someone rent.

There is a massive difference between the family home and a rental property.

Because it is.

Maintenance of your own children isn't covered; to a point - but buying them a house and letting them live in it rent-free would be.

Interesting, to your knowledge has anyone ever been charged tax under this rule?

No. But having not ever been a tax solicitor, accountant, revenue official, or personally involved in such a scenario, I can't imagine how I or the vast majority of people would ever be aware of someone else's tax affairs in this situation.

Also, you aren't "charged" tax under this rule. As with many other taxation rules, you are required to declare it. If Revenue discover that you haven't declared it within the allowable timeframes, you many be subject to penalties and interest

Really? And how has this tax been enforced if the receiver of the 'benefit' has no money.

Can the OP simply grant the sister a right of residence, or conversely maintain a right of residence themselves?

There are legal ways to minimize the tax impact. Deeds of covenant can be effective depending on the individual circumstances.

By the OP keeping a right of residence, the gift would be dramatically reduced in value. Not sure would the OP have to justify their reason for it to the Revenue?

Let's suppose this apartment is owned by the OP and used for her family and friends pleasure and convenience. There are a good many well enough off people who have a house or apartment somewhere that they make available to friends and family. Surely in this case, the OP can facilitate whoever they want use it and it's none of Revenue's business at all. We've borrowed such a house from time to time, no holiday rent paid - none of Revenues business.

If my brother comes and cuts my grass out of the goodness of his heart, it's none of Revenues business that he hasn't charged me and hasn't paid tax on it. Ditto for child minding etc etc. Life is full of arrangements like this between family and friends.

In this case, why can the OP not just let her sister live there and come to some arrangement between them as siblings as to costs of maintenance etc. I can't see any role for Revenue in such an arrangement?

But the OP should get advice on this from professional in the field.