Word for calculating/adjusting a payment when I previously paid too much?

Question

As part of a percentage rent, I need to pay my landlord 10% of my monthly revenue, but no lower than $10,000.

Therefore, I automatically pay $10,000 at the beginning of each month. So let's say we're dealing with January. I pay $10,000, and shortly into February, I have determined my monthly revenue, and 10% of it is $15,000. Now I need to pay an additional $5,000 for January, instead of all 10% of my revenue (because I already put down $10,000).

Now, what is the word for what we did to the 10% of revenue to use only the portion needed to leave the landlord with only $15,000?

Example sentence:

Because I have already paid $10,000, we must _________ the $15,000.

The word offset has been suggested, but I do not think it is an accurate choice.

Also - please make suggestions that fit in the example sentence above, the structure is quite important to my question.

Answer 1

You deduct the advance payment ($10,000 in this case) from the final/total rent payable.

Because I have already paid $10,000, we must deduct it from the total ($15,000).

ODO:

deduct VERB

[WITH OBJECT] Subtract or take away (an amount or part) from a total:
‘tax has been deducted from the payments’

‘Any severance already paid to the workers will be deducted from that amount, the judge ruled.’

TFD(idioms):

deduct (something) from (something else)
to subtract an amount from another amount.
Mr. Wilson deducted the discount from the bill.

McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

Wiktionary:

Verb deduct (third-person singular simple present deducts, present participle deducting, simple past and past participle deducted)
To take one thing from another; remove from; make smaller by some amount.
I will deduct the cost of the can of peas from the money I owe you.

Answer 2

... we must pay the balance.

See also this entry.

Answer 3

Offset is fine, but you don't offset the $15000. You offset the $10k against that sum.

Because I have already paid $10,000, we must offset it against the $15,000.

Oxford's definition isn't particularly helpful, but there is an example which matches, noting how tax liability can be reduced by charitable donations already made:

offset verb
[with object] Counteract (something) by having an equal and opposite force or effect:

‘donations to charities can be offset against tax’

Other examples, showing a slightly different usage:

• The cost would be roughly $1.5 billion, which he says would be offset with spending cuts. [online.wsj.com]
• The cost of the program was partly offset with a $1 million grant from Mercury Insurance. [dailynews.com]

In both usages, offset against and offset with, the larger sum is as stated and the smaller sum is offset.

Answer 4

The overage is exactly the term for the additional increment of rent that you must pay:

overage, 1: Rental increment tied to sales or profit that is in addition to the flat rental fee. Assume a retail store in a mall is charged a base rental of $5,000 per month plus 2% of sales. If sales are $100,000, the overage would be $2,000 and total rental would be $7,000.

So, for your hypothetical month of February, your overage is $5,000, your total rental is $15,000, from which you debit the $10,000 base rental already paid.

To fit your sentence:

Because I have already paid $10,000, we must debit it from the $15,000.

To fit more common usage, the sentence should use the form be debited somehow:

Because I already paid my base rent, $10,000 should be debited from this month's rent of $15,000.

Answer 5

"Because I have already paid $10,000, we must now settle the arrearage of the $15,000."

arrearage:

something that is in arrears; especially : something unpaid and overdue. (Merriam-Webster)

Answer 6

Because I have already paid $10,000, we must remit the amount from the $15,000.

https://www.vocabulary.com/dictionary/remit

"If you’ve been in prison for five years of a seven-year sentence but you’ve been on good behavior, a judge might remit the remainder of your sentence and let you go free."

"release from (claims, debts, or taxes) “The taxes were remitted” Type of: cancel, strike down declare null and void; make ineffective"