Egg donation and surrogacy are both aspects involving third parties to create life.

Anonymity:
Egg donors remain completely anonymous, whilst surrogate mothers enter a formal contract and have a relationship with their commissioning parents.

Age Cut Off:
Egg donors may contribute to the maximim age of 34, whilst surrogate mothers can help up to age 50.

Previous Children:
Surrogate mothers are requried to have had one live child before proceeding.  The is no need for egg donors to have had any children.

Contractual Arrangements:
No formal contract is ratified between recipients and egg donors.  The surrogate mother and commissioning parent sign a formal contract which is approved by the High Court before any embryo transfer may take place.

Pregnancy:
Egg donors do not become pregnant at all.  Surrogate mothers carry the pregnancy for their commissioning parents.

Reimbursement:
Egg donors are offered a fixed donation.  Surrogate mothers may not be paid.  They can be reimbursed for loss of income and expenses associated with the surrogacy pregnancy.

Menstrual Cycles:
Egg donors need to have regular menstrual cycles (unless these are impacted by their specific contraceptives).  Surrogate mothers can be in full menopause, but need a healthy uterus.

Genetics:
Egg donors contribute their genetics to the recipient.  Surrogate mothers carry the pregnancy and contribute no human tissue to the conception.

Psychological:
Both egg donors and surrogates require a psychological assessment to proceed.  For surrogacy, this assessment is much more extensive and requires the approval of a judge.