Should I move my properties into a limited company?

This is the question we are asked more than any other, and it is usually asked in a slightly frustrated way, because the answer online is either "yes, obviously" from someone selling company formations, or "it depends" from someone who does not want to commit.

It does depend. But it depends on a small number of things you can actually put figures against, so here is what they are.

Why the question exists at all

Section 24 changed how mortgage interest works for property held in your own name. Where you used to deduct finance costs from your rental profit, you now get a basic rate reduction against your tax bill instead.

For a lower rate taxpayer with little or no borrowing, that changed very little. For a higher rate taxpayer with mortgages, it changed a great deal, and it is why a conversation that barely happened before is now the first thing most landlords want to talk about.

A company does not work that way. A company deducts its finance costs from its rental profit in full. That single difference is what drives most of the interest in incorporating.

The costs people forget

Moving property into a company is not a transfer of paperwork. In tax terms you are usually selling the property to a company, and that brings consequences that have nothing to do with how much tax you will save afterwards.

Stamp duty. The company is buying, so it generally pays stamp duty on the way in, usually including the additional rates for property of this kind.
Capital gains. You are disposing of the property, so any gain since you bought it may come into charge, even though the money has not gone anywhere.
Refinancing. Your existing mortgages almost certainly cannot come with you. New lending in a company name is a different market, often at different rates, with arrangement fees and legal costs attached.
Running costs. A company has accounts, a corporation tax return and a confirmation statement. That is more work every year than a self assessment return, forever.

None of those are reasons not to do it. They are simply the bill that lands first, before any saving arrives.

The honest version of this question is not "is a company better?" It is "how many years does it take for the saving to repay the cost of getting there, and am I going to be holding this property for longer than that?"

When the answer is usually yes

Taken together, incorporating tends to make sense when several of these are true:

You are a higher or additional rate taxpayer.
The portfolio is geared, meaning there are meaningful mortgages, so the finance cost treatment actually matters.
You are reinvesting rather than living off the rent, so profit can stay in the company and compound rather than being drawn out and taxed again.
You intend to hold for a long time, long enough for the saving to clear the entry cost.
You are still buying, because every future purchase goes straight into the company with none of the entry cost.

When it is usually no

You own one property with no mortgage and no plans to buy another.
You need every pound of the rent to live on, so profit comes straight back out and gets taxed on the way.
You are likely to sell within a few years.
The latent capital gain is large enough that the tax on transferring would take many years to recover.

What to do with that

The decision is arithmetic, not opinion. Work out the entry cost once, work out the annual saving, and divide one by the other. If the answer is three years and you are holding for twenty, it is probably worth doing. If the answer is fourteen years, it is probably not.

There are reliefs that can change the picture significantly for some landlords, particularly where the portfolio is run as a genuine business rather than a passive investment, and they are worth checking before you assume the entry cost is unavoidable.