A taxing time for Mr Brown.
Do you tuck your savings away into a Pep, out of sight of the taxman? Do you uneasily fold your cheque book away when the plumber says 'sorry guv it'll be another pounds 50 if you don't pay cash'?
Between the two lies the wavy line between (legal) tax avoidance and (illegal) tax evasion, or at any rate conniving at the plumber's intended evasion and sharing in his spoils.
Mr Gordon Brown detests the two almost equally.
Naturally, when he sounds off against avoidance, he is thinking of the murky world of offshore trusts inhabited by people like Mr Geoffrey Robinson.
To judge by his actions, though, he is not keen on ordinary tax planning by the not particularly rich.
He is replacing Peps and Tessas by the distinctly less generous Isas. He is stopping tax relief on profit-related pay. He has banned the 'bed and breakfasting' whereby private investors could escape modest amounts of capital gains tax.
Not content with that he has set his officials to work to devise a 'general anti-avoidance rule' - known as GAAR in the trade.
It is a catch-all proposition. If you save yourself tax by arranging your affairs in some way the Parliamentary draftsmen did not imagine when they compiled the bit of tax law in question, you will pay the tax willy-nilly.
Sometime after Easter the resulting GAAR proposal will be published for consultation. Already, though, some tax accountants are sounding of as you might expect. If GAAR performs as advertised and tax dodges routinely cease to work, these are the people w ho will go hungry as rough justice replaces the rule of tax law.
So without waiting for the consultation document the Chartered Institute of Taxation - which would much rather not have GAAR at all - has staked out its ground in a paper of its own.
Mr John Andrews, the Institute's president, compares GAAR to a nuclear deterrent. "It must be a last resort rather than something that will be wielded all the time."
So that it doesn't skew business decisions, the institute wants the Revenue to set up a clearance system which can say in advance it whether or not a given deal or set of deals will trigger GAAR.
To be relevant in a world where business decisions frequently require a response within 30 hours (or 30 minutes) that would entail the taxmen making up their minds within 30 days - or seven days for companies who pay an extra fee for speedy service.
Defiantly, the institute insists that if the Revenue refuses, or fails, to do this because it is too difficult or expensive, GAAR will be "simply unacceptable and unworkable".
I don't see Mr Brown wearing that.
So far as private individuals go, there must be a risk that if GAAR comes down unbearably heavily on legal avoidance people will be tempted to take the risks of illegal evasion and just not declare things.
It happens already in small ways. If you give your son a camera for his birthday and it happens to cost more than pounds 250 you are supposed to declare it for inheritance tax purposes. Hand on heart, do you bother?