Section 17, with other sections of the Bill, provides for a general right of repayment of tax in relation to valid claims made within a four year period. These replace existing provisions on repayments where they are in place. This will apply across all tax heads, except customs duties which are a direct EU tax. The right of the Revenue to make assessments to tax and pursue inquires will also be limited to four years unless it has grounds to suspect fraud or negligence for earlier years.