That depends. It is not always possible to close the reported data (reconciliation). ‘Closing’ means that the closing position can be calculated on the basis of the reported initial position, transactions and other movements. Sometimes, the basis of the reported data (nominal value, market value or units) may vary from column to column. For example, for transactions the transaction value must be reported, while the opening and closing positions are often reported as face value or units.
When you don’t report any sales or purchases (in the case of holdings) or issuances or redemptions (issuance), the reconciliation of the reported amounts must be closing. For debt securities, the reconciliation of the accrued interest must be closing.
Go to Monthly securities reporting to look up the rules per form in terms of reconciliation by downloading the Excel document “Monthly securities reporting annotated templates and assertions”, selecting the ‘assertions’ tab and filtering in column H on the relevant form. All validation rules that are relevant to the form will be displayed, including rules concerning reconciliation.
https://www.dnb.nl/en/statistics/digital-reporting-portal/storingen-en-onderhoud/index.jsp