(18)Counterparties should always assess the legal enforceability of their netting and segregation agreements. Where, with respect to the legal framework of a third country, these assessments turn out to be negative, counterparties should rely on arrangements different from the two-way exchange of margins. With a view to ensuring consistency with international standards, to avoid that it becomes impossible for Union counterparties to trade with counterparties in those jurisdictions, and to ensure a level playing field for Union counterparties, it is appropriate to set out a minimum threshold below which counterparties can trade with counterparties established in those jurisdictions without exchanging initial or variation margins. Where the counterparties have the possibility to collect margins and can ensure that for collected collateral, as opposed to posted collateral, the provisions of this Regulation can be met, Union counterparties should always be required to collect collateral. Exposures from contracts with counterparties established in third-country jurisdictions that are not covered by any exchange of collateral because of the legal impediments in those jurisdictions should be constrained by setting a limit, as capital is not considered equivalent to margin exchange in relation to the exposures arising from non-centrally cleared OTC derivative contracts and not all counterparties subject to the margin requirements under this Regulation are also subject to capital requirements. This limit should be set in such a way that it is simple to calculate and verify. To avoid the build-up of systemic risk and to avoid that such specific treatment creates the possibility to circumvent the provisions of this Regulation, the limit should be set at a conservative level. These treatments would be considered sufficiently prudent, because there are also other risk mitigation techniques as an alternative to margins.