"needed later on" is correct and usable in written English.
You can use it when you want to refer to something that is necessary at a later point in time or that will be useful in the future. For example, "I'll save this information; it might be needed later on."
It's not even clear how long the vaccine lasts, so a booster may be needed later on.
The credit Scott earns - the gamble's payoff - is needed later on, when we learn more about little Bo.
They can accept the losses when they come; but the real effort of gratitude will only be needed later on, when the men come home.
If you deter people, it can just mean treatment is delayed and more expensive care is needed later on".
The personal statement or letter of interest is an invaluable means to provide important information to a prospective employer, program, fellowship, etc., in a way that does not have to indict, accuse, or discredit anyone, especially a mentor who may be needed later on.
You can upscale your plan as needed later on.
This way, you can defrost just the amount you need later on, To prepare, get out of the freezer a few hours before dinner time and let defrost.
For a budding photographer, it might mean taking snaps around the house to practise the fundamentals they'll need later on.
Taking as much money as possible out of my property - to enjoy it while I can, and to possibly finance any care I may need later on - seems like the best idea.
Sue Palmer, a former headteacher and author of the book 21st Century Boys, described the decision as "state-sponsored child abuse", arguing that boys were developmentally behind at birth and needed time to "run, jump and play, in order to acquire the physical control and capacity to focus that they will need later on".
What does matter is that you have a father or a mother or both who make exciting things happen around you, and who do exciting things with you, and who lead you into splendid adventures, for in that way you develop many of the good qualities you will need later on in life, such as courage, loyalty, steadfastness and perhaps above all a sense of fun.
