Large global companies recognize that global compliance and reporting (GCR) risks are increasing, as many countries rewrite their tax codes, step up audits and focus more on tax collection, even as there are also dramatic changes in financing models.

Yet many of these same companies are not taking the opportunity to transform their global compliance and reporting systems, and in some cases are even overlooking “many essential subprocesses” such as the flow of financial data to GCR systems, according to a new report on global compliance and reporting from Ernst & Young.

Based upon interviews with 200 finance and tax executives at Forbes Global 2000 companies, many of which are also in the Fortune Global 500, the report finds that 64% of companies have experienced unplanned tax audits over the past year, while 45% were hit with unexpected tax assessments. Another 42% say they faced penalties while 17% suffered interruptions due to “lack of compliance.”