What term describes the period during which additional surcharges are assessed for late returns?

The term that accurately describes the period during which additional surcharges are assessed for late returns is the "Surcharge liability notice period." This reflects the specific timeframe established by tax authorities during which a taxpayer can incur additional charges if they fail to submit their tax returns by the designated deadline. The purpose of this period is to encourage compliance and timeliness in filing returns, as well as to penalize delays in order to maintain the efficiency of the tax system.

In this context, the other terms do not specifically capture the essence of assessing surcharges for late submissions. The concept of a liability extension period suggests a potential extension for when tax liabilities may be due, rather than focusing on penalties for delays. The late payment period might seem relevant as it denotes a timeframe related to overdue payments, but it doesn’t specifically highlight the assessment of surcharges. The error assessment window typically pertains to the time allowed for the tax authority to review and adjust assessments based on errors, rather than on late submissions and the corresponding surcharges. Therefore, "Surcharge liability notice period" is the most precise term for the situation described in the question.