It depends on baby’s acceptance as well. I tried to transit my LO from bm to UHT/FM when she turned one but she gets very bad constipation from UHT (we tried a lot of brands). Not very good with solids as well for the first 2 years so we gave formula so she can at least have the nutrients from it. Now that she entered school and eating solids well (but she’s still on the smaller side), we tried to offer UHT but she didn’t want so we continue FM.
can slowly transit to UHT milk if you prefer convenience. just need to bring the small packet out. but should look at the ingredient list, not all UHT milk are 100% fresh milk. can consider greenfields, they come in small packet of 100ml. super convenient. https://s.lazada.sg/s.VG26i