Announcing business rates reform was the easy bit. Now the chancellor has to work out what changes to this £26bn tax revenue stream will be fairer, pro-growth, fiscally responsible and popular.

There are two key decisions to make. First, what level of contribution does the chancellor want business rates to make to the public purse? Because business rates go up by inflation, the Treasury’s take goes up even when the economy struggles, while corporation tax, income tax and VAT income vary with economic performance. This is one reason governments of all shades have traditionally liked business rates – they are stable and hard for firms to avoid.

There is a strong case for business rates to be scrapped with the whole business tax burden falling on profits, but the chancellor regards reducing corporation tax as one of his landmark achievements. While we believe that the chancellor should consider all options, some ideas – like basing business rates on sales – would be worse for many.

The second question is how to apportion the burden of business rates. Most sectors feel they pay too much, but they can’t all be right.

Online businesses have to come under scrutiny, as they trade from remote locations, attracting low business rates compared with their high street competitors – one Amazon warehouse in Wales is reported to have a rateable value of one-fourteenth of that of a business in the town centre (£29.10 per sq m instead of £416 per sq m).

Maybe a separate rating scheme for online businesses would be a good place to start as the chancellor negotiates this hazardous road.