The storage guideline is as below:
The following are merely guidelines and do not provide any assurance of quality.

Refrigerator (4°C or below) Freezer (around -18°C)
Freshly pumped breastmilk 24 hours 3 months (recommended)
6 months (usable)
Thawed breastmilk (Thawed in refrigerator or under running water) 24 hours* Do not refreeze.

* If thawed by immersing in warm water, do not place back in the refrigerator.