Upto or Up to? Which is correct?

Up to is correct and upto is incorrect. Up to is usually used to describe a number in a range before another number. Up to should always be two words.

I am free up to the fifth of May.

You can write up to 1,000 words for your essay.

Your prize includes flights up to $2,000.

Upto is a common misspelling of “up to”. “Up to” should not be used in English. 

Up to

Up to has a few different meanings and can be used in the following contexts

Within a time or physical range (where the maximum point is highlighted)

We often use “up to” when we want to show something must be less than a specific point and we want to highlight the limit. 

You are free up to a point.

You have up to three shots to win the prize. 

Until 

Up to can mean something similar to until in informal English when in the context of time.

I will be available for meetings up to the 15th of October.

Engaged in (sometimes suspiciously)

Up to can mean “doing something”. This can sometimes be in the context of scheming something.  

What are you up to? I know you are up to something suspicious.

Responsibility

We use “up to” when we want to show who has the responsibility.

It’s up to you, I don’t care.

Upto

Upto is incorrect in English and you shouldn’t use “upto” in written English. Some prepositions come together to form a new word like “into” or “onto” but this is not the case with “upto”.

Conor