esiste anche l'irrebuttable presumpotive assessment, ma credo che nel tuo caso si applichi la prima definizione.
Forse anche semplicemente "presumptive assessment", non so se la distinzione vada necessariamente fatta nel tuo caso, giudica tu.

Naturalmente il tutto deriva da "presumptive (income) taxation" e "presumptive tax"

Media confidenza perché è una risposta amatoriale, non sono un'esperta, ma credo abbia senso. Verifica e attendi pareri.
In ogni caso, buon lavoro. Ciao!!!

Ti metto un po' di ref.

Legal Characteristics of Presumptive Methods
A. Rebuttable vs. Irrebuttable
Presumptive methods can be rebuttable or irrebuttable. Rebuttable methods include administrative approaches to reconstructing the taxpayer's income, and may or may not be specifically described in the statute. If the taxpayer disagrees with the result reached, the taxpayer can appeal by proving that his or her actual income, calculated under the normal tax accounting rules, was less than that calculated under the presumptive method.
By contrast, irrebuttable presumptive assessments should be specified in the statute or in delegated legislation. Because they are legally binding, they must be defined precisely.
Rebuttable presumptive assessments are a universal feature of tax assessment procedure, required in order to deal with cases where taxpayers either do not fully disclose their financial situations on their returns or fail to file a return. In these cases, the law normally authorizes the tax authority to use indirect methods to determine the taxpayer's income, based perhaps on arbitrary criteria or on whatever data are available.
Because presumptive assessment is intended as a means of ascertaining the taxpayer's income in the face of inadequate data, the taxpayer should be allowed to present better data to refute the determination of the tax authorities. This type of presumptive assessment therefore does not represent a fundamental departure from the normal rules for determining tax liability, but is a fallback when these rules do not work because of
noncompliance by the taxpayer
http://www.imf.org/external/pubs/nft/1998/tlaw/eng/ch12.pdf

http://www.tesionline.com/__PDF/16306/16306b.pdf (guarda la biblio)


su presumptive taxation:
http://isp-aysps.gsu.edu/academics/conferences/conf2003/Thur...

http://books.google.com/books?ct=result&ie=ISO-8859-1&output...