We posted the Verizon forms for the low-cost sale of our shares on the same day. The receipts that came back to us showed that all the transactions were carried out on the same day (January 19th). Two of them had the same Trade ID and the average price per share was £40.455957.

The third had a different Trade ID and the average price per share was £31.139587! That's a £9.30 price per share difference.

I rang the UK phone number at the top of the letter and the only explanation I got was that it was either down to different dealers or share price volatility on the day. Surely that cannot be right?

Mr LC, Dublin

It can’t, and, to be fair, on second sight after sending me your query, you noticed that some of the amounts (the higher ones) were in euro and the lower ones were in sterling.

The answer is, in fact, ridiculously simple. It has nothing to do with different dealers or share price volatility. While one might expect shares trading in London to do so in sterling, Verizon trades on the London exchange in dollars.

On the date in question, the trading range of the Verizon shares was $44.20-$44.98. They’ve gone higher since, but that is of no use to you.

That would translate at about €40.54-€41.25 a share or, if using sterling, £31.19-£31.75. The prices quoted to you are only fractionally below that, a difference almost certainly explained by the commercial foreign exchange rate used.

So there is no conspiracy. And had the person on the other end of the phone when you rang Bristol thought through the query, they would have been able to put your mind at rest, or at least to admit they simply didn't know and pass you on to someone else who might. I can't say for sure, but I'd imagine, given the brouhaha over Irish shareholders and Computershare over Vodafone, that the main switchboards are probably aware of the special Irish shareholder helpline.

While there might of course be differences between one dealer and another, it would never account for the scale of difference you initially thought lay between the price received on the same day for two tranches of shares.

Equally, a volatility that caused the price of a company such as Verizon to swing by around 25 per cent in a trading day would not pass unnoticed.

One thing I would say is in relation to contacting Computershare with any queries about the sale of Verizon shares. You used the UK number at the top of the letter giving details of the transaction, but this is a general Computershare UK number. You would have been much better advised using the dedicated Verizon shareholder helpline number: 01-6968421.

I’m not excusing the pretty pathetic explanation given to you when you made your call, but you might have got greater clarity had you contacted the team that is specifically briefed on the various issues around the Verizon shares – and the Irish shareholders.

Of course, even a low-cost dealing service has charges – not that you are contesting this.

The “commission” for the low-cost dealing service is 0.5 per cent of the value of the trade, with a minimum charge of €17. For many Irish shareholders who hold just a handful of shares, the €17 is the relevant figure.

For comparison, the “standard” charge for online dealing in Verizon shares would be 1 per cent, with a minimum of £20. Using the normal telephone dealing service would cost 1 per cent of the trade value plus £25.

If you look at the 202,000 Irish Verizon shareholders at the start of this low-cost dealing service last November, half have three or fewer shares.

If you take the $48 share price for Verizon last week, the Irish holder of three shares would receive €112.07 after conversion to euro and subtraction of dealing charges under the low-cost system. If done online under normal conditions, the new proceeds would be €97.07, and just €89.07 for phone trades.

The situation for the almost 50,000 Irish people with just one Verizon share is even more stark. Under the special dealing service currently on offer, you would get €26.02 after charges and conversion to euro. Using the normal online service, your net proceeds would be less than half that figure – €11.02 – and an even more miserly €3.02 using the normal phone dealing service.

For those who have yet to contact Computershare about their Verizon shares, time is running out. The low-cost dealing option expires on February 17th, just over two weeks from now. Thereafter, the cost of selling the shares – especially for those with just one or two of them, as so many Irish shareholders have – will return to being prohibitive: $25 per trade plus $0.12 per share.

You will also face having to deal with the US tax authorities over dividends and will be required to contact a share registrar in the US with any queries you may have over your holdings.

Those with just a handful of shares really should seriously consider why they would want to remain invested.

Send your queries to Dominic Coyle, Q&A, The Irish Times, 24-28 Tara Street, Dublin 2, or email dcoyle@irishtimes.com. This column is a reader service and is not intended to replace professional advice