I have a Ideal Standard toilet with a internal flush, the problem is after every flush it continues to overflow after it as filled is this a simple repair I could carryout myself and are any special tools required
Unless you can provide some pictures of your particular flush valve/syphon and float valve, then it's difficult to advise you on how best to solve the problem.
The most likely reason the toilet is overflowing is either the float valve is passing water or the flush valve isn't seating properly.
The way to test this is to turn the water supply off to your cistern, then watch what happens. If the overflow problem still occurs and the water level gets lower and lower, then the problem lies with your flush valve. If water reduces to the overflow level and the problem rights itself, then the fault is with the float valve.