We don't have enough money *on/in* hand to finish this project.

[z7655431]

"We don't have enough money on hand to finish this project." (NEW TOEIC phrases, Ivy)
Is the use of on hand correct here? How about in hand? I found that both Longman and Oxford Dictionaries list the collocation of having money in hand.

From Longman Business Dictionary:
6. time/money etc in hand extra time or money that is available to be used
The report is not finished yet, but we still have some time in hand.

From Oxford Learner's Dictionaries:
​if you have time or money in hand, it is left and available to be used
We managed to redecorate the house and still have some savings in hand.

But the weird thing is.... On Lugwig, the use of having (enough) money on hand is much more frequent than that of having (enough) money in hand. I'm so confused. Please help me with this. Thanks!

 

[jutfrank]

There's a difference in meaning between in hand and on hand, which I understand like this:

If something is in hand, it is in possession. Think about something being literally in your hand.
If something is on hand, it is available to use. Think about something being near your hand.

In many cases, including cases about money, there's very little, if any, practical difference, which explains the confusion you're having.