Last month, Sir James Mirrlees, the Nobel laureate economist, presented the results of a fundamental review of British taxes under the auspices of the Institute for Fiscal Studies. The report highlighted some interesting anomalies in the tax system. For instance, at the top of the income distribution, marginal tax rates rise to 40%, then 60%, fall back to 40% and then rise again to 50% - the effect of gradually withdrawing tax allowances above an income of £100,000 a year. At the bottom end of the scale, the situation is even more confusing. The report includes a case study involving a single parent whose take-home income can be anything from £220 to £300 as the earnings vary between £0 and £230. The marginal rate of tax for someone in this position can be as high as 80%. This is because of the strange system of tax credits and the way benefits work. Mirrlees points out that it would be possible to raise the same amount of tax, with roughly the same distribution of income, more efficiently. This is obviously true. However, his ideas for changing child tax credits, NI and pensions strike me as no better than the present arrangements. The trouble is that none of the people involved in the tax system - the government, the opposition, HM Revenue & Customs (HMRC) or the accountancy profession - have an incentive to really change and improve it.

My 20-year-old son has just cooked me an £11,000 omelette - this being the cost of the cookery course I paid to send him on earlier in the year - and at this juncture there seems little hope that either he or his brothers will support me in my old age. But it costs nothing to dream and I obviously hope that, should their fiscal future turn out to be better than my own, they will come to their father's aid.

One good way in which they might do this is to lend me money to be repaid out of my estate. This has obvious advantages. I could stay in my own home, it would reduce my inheritance tax (IHT) bill and my children would have plenty of security. But such arrangements can be challenged by HMRC on the grounds that the loans are 'past consideration'. Basically, this means that you can't repay a debt for services previously rendered without a formal agreement in place.

The golden rule, whether you are lending or borrowing, is to put a written agreement in place on day one and to get it checked by a tax adviser and/or solicitor to make sure it will withstand future scrutiny.

A growing number of people with relatively valuable homes are becoming landlords as a temporary way of overcoming the effects of the recession or simply because they want some extra income. This is, of course, a subject that we cover regularly in TSR, but I thought it may be worth just summarising the key opportunities.

The first is rent-a-room relief, which allows you to rent a room out in your house and claim £4,250 of income tax-free. It can't be used in a second home but it can apply to a caravan or houseboat and in some instances even to income from a bed and breakfast. You make the claim on a self-assessment form and if it is your main home and the tenant lives with the family it shouldn't affect the capital gains tax position if you come to sell.

Where you let one or more furnished rooms it may be more advantageous for you to operate under the 'furnished lettings' rules. These allow you to claim all your expenses against the income and although there are no capital allowances a 10% wear-and-tear allowance can be claimed. Expenses can include mortgage interest (not capital), utilities, council tax, insurance, cleaning, accountancy, bad debts and so forth. The same rules (with the exception of wear and tear) apply to unfurnished lettings.

It is also worth mentioning that if you set up as a bed and breakfast or guest house you may be able to claim lettings relief for capital gains tax purposes and/or inheritance tax business property relief.

Finally, I will just say that I have always wondered how many landlords there are in the UK letting rooms in their houses for cash and not declaring some or all of it. My guess is that the practice is surprisingly common because the chances of getting caught are so slim - but maybe I am just being cynical.

I was interested to see that the Treasury now expects to receive £10 billion from tax treaties with Lichtenstein, Switzerland and three other, as yet unnamed, jurisdictions. This is against an original projection of £2 billion from Lichtenstein alone. As usual, of course, no mention has been made of the biggest tax haven of them all - the USA - where states like Nevada and Delaware offer 100% secrecy and zero tax to offshore businesses.

Invest in a community development finance institution (CDFI), the organisations that provide finance to ventures in deprived areas, and you can claim 5% relief per year over five years. That may not sound like much but with the base rate hovering around 0.5% it may be a better way to employ one's unwanted capital. There is a small element of risk (that should not be ignored) but by and large this is a relatively safe investment. If you are interested to know more, search online for CDFIs.