Revisions process

Trade in goods data is revised on a continuous, rolling basis. A large component of the monthly revisions comes from incorporation of late data received from traders which replace estimates for previous non-response. Revisions also arise where data received from a trader has been queried and the data is found to be incorrect.

All revisions are incorporated into the latest CSO release and PX-Stat tables and submitted to Eurostat each month. Due to the continuous nature of revisions, the changes are not normally highlighted.

Changes to trade data collection following Brexit

From 1st January 2021, all trade in goods with Great Britain (excluding Northern Ireland) must be reported to Revenue’s Customs declaration systems. Prior to this, data on trade with Great Britain were collected via a combination of the Intrastat survey and VAT returns.

Under the Revised Protocol on Ireland and Northern Ireland, Northern Ireland effectively remains within the EU Single Market for the movement of goods, and trade statistics with Northern Ireland continue to be compiled from Intrastat survey data and VAT returns. As part of the new rules, separately identifiable VAT numbers for Northern Irish entities were introduced from January 2021.

This introduction of Northern Irish VAT numbers has allowed traders to identify and report trade with Northern Ireland more accurately. Previously it was not always possible to distinguish whether a UK VAT number related to a trader in Great Britain or Northern Ireland.

Identification of revisions

Where a large increase in trade with Northern Ireland was recorded since the start of 2021 the data have been queried with traders. In many cases, the increases are explained by changes to supply chains.  However, in some cases, traders have reported that they had previously been incorrectly reporting their trading partner as Great Britain, when in fact the partner should have been a trader in Northern Ireland.

Where errors in historical data have been identified, the data has been revised by the CSO for a period of two years (2019-2020) to allow more accurate comparisons of Ireland’s trade with Northern Ireland before and after Brexit.

Size of revisions to trade with Northern Ireland

Since the beginning of this year, exports to Northern Ireland have been revised upwards by a cumulative total of approximately €250 million for 2020 while imports have been revised upwards by approximately €450 million for 2020.

The sectors with the largest revisions were exports of Food and live animals to Northern Ireland, where exports were revised upwards by €185 million in 2020, and imports of Chemicals and related products from Northern Ireland, which were revised upwards by €218 million for the same period.

Trade in goods with Great Britain has decreased by similar amounts as these improvements to regional allocation have been implemented. Therefore, trade with the UK as a whole is largely unchanged by these revisions.

Table 1 gives details of the changes to 2020 data. The data for 2019 were revised by similar amounts across the same sectors.