"Apportionment account" is one option but it depends on the context.
Apportionment: the allotment of direct taxes on the basis of state population.

For example it can even be used in military lingo (Ex: third definition for allotment (Webster's II New Collee Dict.
3. Allotment: a portion of a militqry person's pay set aside for his or her dependents or for insurance.)

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Note added at 16 mins (2005-04-01 07:38:01 GMT)
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In general terms, an allotment account could probably be set up for either fixed or unforeseen expenses that are going to be incurred.
Do you have more context? What kind of project are we discussing here?

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Note added at 19 mins (2005-04-01 07:41:03 GMT)
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Some examples found on internet (of which a mention is military).
It can even be a contingency type of account as I had mentioned above for expenses that are going to be incurred (unforeseen).

Open an Allotment Account
Open an Allotment Account. Please fill out this form online, print it, and then mail it to us at the address below. Which Branch of the Service are you in: Navy. Army. Air Force ... I authorize payments from my account that are not covered by my ...www.nbstamford.com/forms/allotment_account.htm - 17k - Cached - More from this site
45.770 Contingency account. (1) There is created within the capital construction fund the capital construction and (PDF)
... equipment purchase contingency account to the allotment account of an ... and equipment purchase contingency account to the allotment account of the ...www.lrc.state.ky.us/KRS/045-00/770.PDF - 8k - View as html - More from this site
To print in an IUB computing lab or library, what computing accounts do I need?
To print in an IUB computing lab or library, what computing accounts do I need? Registered students and faculty are automatically entitled to a printing account. ... may purchase an account or add a supplemental allotment to an existing account. To do so ...kb.indiana.edu/data/ahnt.html?cust=809935.38406.131 - More from this site
I TFM Part 3-CHAPTER 6000: PURCHASING U.S. SAVINGS BONDS, SERIES EE AND I, THROUGH THE VOLUNTARY PAYROLL SAVINGS ...
... of termination, the balance in the employee\'s allotment account is insufficient to purchase a bond, the ... any balance in the employee\'s allotment account as soon as practicable after ...www.fms.treas.gov/tfm/vol1/v1p3c600.html - 41k - Cached - More from this site
Charter School Financial Guide

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Note added at 1 hr 14 mins (2005-04-01 08:36:09 GMT)
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I\'ve seen it also in the context of Savings Account Lingo for both civilians and military

Here is some expression for allotment (account) : "When gasoline is scarce, rationing will assure that each driver gets his fair allotment. The company gives me an allotment of $15 a day for traveling expenses."
I would say " a budget " account, when they cannot spend more daily, monthly, quarterly as the contract allows them.