Tax officials have realised that some people using eBay are professional traders! Your own unwanted personal belongings can certainly be sold without any tax problems, but if you deliberately buy something and then sell it on at a profit, you are actually running a small business. You need to keep a record of all your sales, and how you came by the goods in the first place. I can tell you that tax inspectors are using a tailor-made internet search engine of their own to spot people who do a very large amount of business on eBay. So either you have been caught in their net or, if you really are just a small time trader, you have been very unlucky.

I am not the sort of person who buys stocks and shares, but I was given a small number of shares when one of the building societies turned into a bank. As I am getting on and have no dependents, I thought I might donate them to charity, but I do not know how to go about this. Mrs L.G.

An organisation called Sharegift (0207 930 3737) specialises in collecting small shareholdings and turning them into cash for charity. It will give you a transfer form to sign, and this is the only paperwork you need do. Sharegift will do the rest.

My wife and I would like to buy some premium bonds for our five-year-old grandson. Can we do this in our own names? We are afraid our son-in-law might cash the bonds if he has them. H.S.

You can certainly apply for the bonds, but legally you must give National Savings (0845 964 5000) the name of your grandson’s parent who will receive any prize money. You could, of course, just give your daughter’s details. The other option would be to buy bonds in your own name but make a mental note that they are really for your grandson. This might lead to inheritance tax problems though, if you had a very big win.

My mother has been told that when her electricity meter was changed in 2005, the company muddled up the night tariff and the day tariff. She has been told she owes £300, which she agrees is about right, but should she pay as it was not her mistake? Ms P.C.

When someone has run up a bill that is their responsibility but not their fault, the company will often settle for a lower sum. If your mother’s electricity supplier demands the lot, complain to the watchdog organisation Energywatch (08459 06 07 08). As a rule, it does not allow back-billing for more than two years.