Hi all - First of all I’m new to T212 but just wanted to clarify a couple of things with regards to dividends on T212.
-How long do I have to have owned the stock for prior to the Ex Div Date?
-If I sell the stock after the Ex Div Date but prior to the payment date - will the dividends still be paid?
The close of the day before.
Yeah it will still be paid.
Be careful with this, the share price will decrease by the amount of the dividend, so the capital losses may offset the the dividend gain
Many thanks - I didnt know this. Can you explain this a bit further…
Why would the share price decrease? I understand the risk of the share price reducing more than the cost of the dividend and then making the purchase irrelevant, but why wouldnt I get the sell price?
Perhaps you can read this article and follow some of the hyperlinks for further clarifications.
I find Investopedia very helpful for learning the basics. 
Ex-dividend means excluding dividend. I.e. the day the share trades with the value of the dividend removed from the stock price.
Well just think of it like this. A company’s share price is just based on the value of the company, more specifically how investors value the company as they’re the ones who choose how much to buy and sell the share for. But as soon as the company pays out say £0.10 on a £5 share, the company no longer has that cash, so now the company is worth £0.10 less per share. Basically it doesn’t matter when you buy a share, because that £0.10 will be there somewhere in theory, whether that be in cash in your hand or in the value of your shares.
Basically in theory you could buy the £5 share before the ex date and get 10p to buy you an extra 0.02 shares in the company, or you could buy it on the ex and buy 1.02 shares for £5. Both will arrive at the same outcome. Sorry for waffling but I hope it helps.