Taxes (TAX)

[cintrix]

We had to sell some stock on my mother-in-law's behalf. I think we sold around 800 shares of T and it came to about 30k, now we have to sell another 200 shares of it and we have to sell her VOD stock. Problem is we have no idea what the cost basis is. She got this stock which was from her deceased husband who died in the 1970's (I'm thinking her cost might be the date of his death) - he worked for the phone company. So he must of had a good amount of his telephone company stock before the divestiture. Then all those baby bells came about and spin offs and mergers. I haven't a clue what to use as a cost basis. Do I have to use 0 on her return for a cost since I don't know? That would be a lot of tax to pay.