Holding a long position in 20,000 shares of XYZ Corporation will entitle you to the dividend payout, providing you hold your position after the close the day before the ex-div date. If the company is going to pay a dividend of 12p per share, and assuming it is a UK company, you will receive100% of the dividend declared. So a total of £2,400 will be credited to your account. And it will be tax free!
If you are long in US shares, the net dividend credited to your account will be 85% of gross dividend. So for example if you are long 35,000 shares of ABC and it declared a payout of 20 cents per share, you will be credited $5,950 (85% of $7,000 = 0.20 x 35,000).