Cross-border estates are not unusual. They are increasingly ordinary. A UK family with Swiss accounts. A US citizen with UK property. A family with passports in two jurisdictions, children in a third, and assets scattered across multiple banks because 'it made sense at the time.' The estate planning profession treats cross-border cases as complex edge scenarios. They are not edges. They are default reality for globally mobile families. The complexity is real. But the principles that address it are knowable.
The three common breakpoints
Account access is the first blockage. A UK executor attempting to access a Swiss bank account after the principal's death encounters Swiss banking requirements: local probate documentation, translated instruments, notarised authority, and compliance processes that can typically take 4–8 months. During that window, account access is frozen. Forced heirship is the second problem — some jurisdictions impose statutory inheritance rules that override testamentary freedom. Tax treaties determine the third set of complications: double taxation, withholding, reporting obligations.
What 'planning' actually requires
Cross-border estate planning does not mean 'one global solution.' It means jurisdiction-specific instruments that work together without contradiction. A UK will covering UK assets. A Swiss will covering Swiss assets. Powers of attorney drafted to meet the requirements of both jurisdictions. The instruments must not contradict each other: a Swiss will should not accidentally revoke a UK will. This requires professional coordination across jurisdictions — multiple solicitors who know each jurisdiction's rules and can draft instruments that interoperate.
Apostille and document authentication
Many jurisdictions require authenticated documents for cross-border recognition. The Hague Apostille Convention standardises this process: a certifying authority attaches an apostille stamp, and other treaty countries accept the document as valid. For cross-border estates, preparing apostille-ready documentation in advance eliminates delays during execution. One day of administrative work avoids months of remediation.
Liquidity bridges
If cross-border accounts are frozen for 4–6 months during probate, how does the estate meet ongoing obligations? The standard solution is a liquidity bridge: accessible funds in a jurisdiction with fast probate that the executor can reach quickly while cross-border accounts remain frozen. Three to six months of operating expenses — £20k–£50k for most families. Having it accessible in a quickly-clearing jurisdiction prevents crisis funding needs during administrative delays elsewhere.