If one is in ihram for Hajj or Umrah, it is not permissible for him to intercourse until he or she has exited ihram. If a person has intercourse before completing umrah, his umrah is invalidated. However he must complete it and perform it once again by entering ihram from the place he entered it the first time, as well as sacrificing a sheep on behalf of each of you, to be slaughtered in Makkah and its meat distributed to the poor (of that city).
However, if intercourse takes place before shaving the head or hair cutting and after saai than that does not invalidate umrah but a fidyah or ransom must be offered for that (the choice can be made from the following three: between offering a sacrifice, fasting for three days or feeding six poor persons).
Shaykh Ibn Baaz (may Allah have mercy on him) said: If you have intercourse with your wife, it invalidates your ‘Umrah, but you have to complete it, then make it up again from the place at which you entered ihram the first time. And you have to offer a sacrifice, which is a one-year-old sheep or a two-year-old goat, to slaughtered in Makkah and given to the poor. One-seventh of a camel or cow is also acceptable.
End quote from Fataawa Islamiyyah.
Some scholars are of the view that what is required of one who has intercourse during ‘Umrah is to offer fidyah, with a choice between offering a sacrifice, fasting for three days or feeding six poor persons, whether he had intercourse before saa‘i or after, as it says inSharh Muntaha al-Iraadaat, 1/556.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: ‘Umrah in which intercourse takes place is an invalid ‘Umrah and you have to sacrifice a sheep, to be slaughtered in Makkah and the meat distributed to the poor; or feed six poor persons, giving each one half a saa‘ of food; or fast for three days. You also have to do another ‘Umrah to make up for the one that was spoiled. End quote from al-Liqa’ ash-Shahri, 9/54
Following three things must be done:
1. Repent sincerely for breaking and spoiling the umrah and not following the commands of Allah with regard to such holy actions.
2. Do Umrah again to make up for the spoiled one. Enter the ihram from the same miqaat as was entered for the umrah that was spoiled.
3. Offer a fidyah( ransom) sacrifice in the way of Allah. As mentioned above the choice can be made from choosing one of the following three: sacrificing a sheep, or fasting three days, or feeding six poor people among the poor of Makkah. If each of you sacrifices a sheep, that is preferable and is more on the safe side.
And Allah knows best.