13. To support the arm's length nature of intra-group transactions, both the taxpayer and the tax administration have various possibilities for obtaining evidence. These range from the preferred source of information readily available within the company or group (internal comparables) to external comparables that can be obtained from a variety of sources, including searches of databases when the latter satisfy the comparability requirements and the rules on the aggregation of transactions. The Forum agreed that tax administrations should evaluate domestic or non-domestic comparables with respect to the specific facts and circumstances of the case. For example, comparables found in pan-European databases should not be rejected automatically. The use of non-domestic comparables by itself should not subject the taxpayer to penalties for non-compliance.
