For flat moles apart from the above you can try
1.Onion juice is a very simple ingredient that helps in removing the flat moles. Simply crush or grind the onion, press the ground mixture via a fine cloth, apply a few drops of the extract over the mole and after about half an hour wash it, this method needs more patience as it takes a longer time.
2.Honey and flaxseed oil in equal amounts can be mixed and applied on the area and after about 30 minutes please wash it off.
3.For persistent flat moles, you can try castor oil mixed with baking soda (just a pinch), apply it to the mole and cover with a small self-adhesive medical plaster. After 2-3 hours remove it and wash the remnants.
Please remember two things
A. All the natural ingredients either reduce the colour or are acidic or dry out the mole area, so please be careful when you apply these for a longer time as the surrounding skin can get damaged. You can use a little bit of face moisturizing cream or vaseline around the mole so that you protect the rest of the skin in the vicinity.
B. If the mole increases in size or has crustations or bleeding, please see a qualified dermatologist.