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Each family member builds the record
Daysium Mobile keeps day counts current against the rules set for that person and builds the record as they travel.
For family offices
One place to oversee residence across the family.
Daysium gives your office one governed process for day counts and evidence across the family, while each family member stays in control of who sees their position.
The process may work
Managing the year is one thing. Evidencing it later is another.
The office carries the process
Boarding passes, travel summaries, spreadsheets and weekly checks can keep the process moving — but they also create work that may have to be reconstructed later.
The family does not move as one
Different family members can have different jurisdictions, rules and advisors. One family can have several residence positions in play at once.
Scrutiny changes the job
If a position is challenged years later, the question is whether the underlying facts and evidence are already there.
Built for later, as well as now
The record can matter long after the journey.
Tax returns, enquiries, changes of advisor and estate administration can all put historic residence back under the microscope.
Daysium records are already being used by professional advisors in live tax enquiries.
One process, with clear roles throughout.
Private. Permissioned. Governed.
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The office supports the process
With permission, the office can work from the live position, reconcile it against other records and help keep the process organised.
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Advisors work from the current position
Whether in-house or external, named advisors can work from the live day-count position and reports.
The office gets visibility.
Each family member keeps control.
Inside Daysium
One platform. Separate records. Permissioned access.
Each family member uses Daysium Mobile. It keeps their day counts current against the rules set for their position and builds the factual record as they travel.
Location-derived records, assumptions, corrections and supporting evidence build through the year, with provenance preserved in the audit trail.
Reports provide a point-in-time record when the position needs to be shared or retained. Daysium Vault can preserve the historic Daysium record and day-count summaries after active membership ends.
Named family-office staff and advisors can see the live position and reports each family member chooses to share.
In practice
A better process across
the family.
Current. Coordinated. Continuous.
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Current through the year
Each family member builds their own position as they travel.
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Separate by design
Different residence positions stay distinct, even when supported through one family-office process.
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Visible with permission
The family office sees the live position each family member chooses to share.
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Ready to carry forward
The record remains available as advisors, jurisdictions and responsibilities change.
One process across the family, without treating the family
as one residence position.
Built with experience
Designed around real family office workflows.
Daysium has been shaped with family offices, private-client advisors and internationally mobile families around the practical realities of missing data, privacy, access, reporting and later scrutiny.
Valuable Partnerships
A pioneering company in the field of day counting and record-keeping. Their innovative tool simplifies complex date-related calculations, offering immense value to our clients. This partnership marks a significant step towards enhancing our client services with advanced solutions.
Alan Kennedy,Managing Director,Trident Tax
Exciting technology
The technology that Daysium has developed is incredibly exciting. The team's passion and vision for solving the ongoing nightmare of residency status is brilliantly evident.
Rhys Thomas,Managing Director,WTT Group
Fantastic product
We found out about Daysium from our advisors. It's a fantastic product, very easy to use, with someone on the end of the phone if needed. We would and have recommended it to anyone that would need such a product.
Nick T,Monaco No more spreadsheets
After more than two decades of manually counting days spent in various jurisdictions using Excel, I discovered Daysium. It's transformed how I track my whereabouts — automated, precise, a defensible record ready for when I need it.
Sanjeev P,Zurich
Founding partners
Frequently asked questions
Does the family office automatically see everyone’s data?
No. Each family member decides which named people can see their position and reports.
Does Daysium replace the individual’s role in their own residence record?
No. The individual remains part of the process. Daysium reduces the manual work of counting and recording days while keeping assumptions, evidence and corrections visible.
What happens if my phone does not provide location data?
Daysium records an assumed day based on the previous known location. That assumption remains visible and can be reviewed or corrected using the available travel information. Daysium does not hide missing data or pretend an assumption is a confirmed location.
Can the family office and external advisors both be involved?
Yes. Each family member can give named family-office staff and external advisors access to the position and reports relevant to them.
Have Daysium records been used in a tax enquiry?
Yes. Professional advisors are currently using Daysium records for clients involved in live tax enquiries. Daysium does not claim HMRC endorsement or that a particular outcome resulted from using the platform.
What happens when somebody stops being an active client?
Daysium Vault provides a retention option for preserving the historic Daysium record and day-count summaries after active membership ends.
What happens when advisors change?
The record stays with the family member. A new named advisor can be given access to the current position and reports, while historic records can be retained through reporting and Daysium Vault.
Recognised by
Finalist two years running at theDigital Jersey TechAwards2024 – Startup Category2025 – Fintech, Startup
#2 Most Recommended StartupOut of 3,000+ companies, Daysium was ranked 2ndin a live, AI-powered scoring of Europe’s topstartups by global VCs & investors
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In essence
There's nothing to see here — everything is in order.
Each family member keeps control of their own position, the office has the visibility it needs, and the record is there when a family member or advisor needs it.