A lot of the budget is known. But not everything . Here are five things we still don’t know.

1. Will there be any tax clawbacks?

Possibly not many. All taxpayers will be left better off. But there had been talk of clawing back some gains from lower earners via lowering the limit at which PRSI is paid. And there have been changes to hit higher earners in recent years and limit gains for cuts in the main USC rate.

With more limited gains from USC cuts this year, clawback may not be judged necessary this time. This would mean straight gains from USC cuts for lower earners. And for those in the higher bracket, everyone earning €70,000 or above would get the same cash gain from the USC cut. With numbers tight, this is an area to watch.

2. What will happen with the vulture funds ?

Measures are promised to ensure so-called vulture funds don’t use financial legislation – so-called section 110 companies – to avoid paying tax on assets bought and sold in Ireland. There is also the issue of the tax treatment of special vehicles such as qualifying investment funds (QIFs) and Irish Collective Asset Management Vehicles (ICAVs). There has been a massive lobbying campaign by the funds industry in response to an initial proposal on the section 100 and political comments that the other fund structures would be targeted. Some change will happen but how will they be structured to catch the intended targets but avoid hitting the international funds industry?

3. When will everything happen?

We have seen the debate over when the pension and welfare increases will kick in. There is scope to tinker with the timing of a vast range of tax and welfare changes to save money in 2017. Also , the Budget will be presented as the first in a three year series – and it is worth watching what commitments are made for future years .

4 . What will “ Brexit proofed” mean? Exactly?

One theme will be helping business and entrepreneurs. There will be measures to help entrepreneurs via a special 10 per cent capital gains tax rate for those selling their business and new reliefs for share based remuneration. But the key question is what the terms and conditions are on these. Previously entrepreneurs have criticised them as far too restrictive. There will also be close attention paid to schemes introduced to help exporters target new markets and gain access to funding . The State-owned Strategic Banking Corporation of Ireland will be central to this. Again the key issue will be the terms and conditions.

5 . How will it all add up?

Another key area of “Brexit proofing” is aiming to improve the public finance quickly, to give room to manoeuvre in the face of volatility. But with all the pressures to spend more and tax less, just how low a budget deficit will be aimed for. Indications are around 0.5 per cent of GDP. Some money found in “savings” from departmental spending this year may help to square the circle – providing a bit of extra cash without pushing borrowing higher.