Support
Need help with an import, scheduling or reminders? Email us with your device, app version and a brief description.
EMAIL SUPPORTsupport@call-stack.deCommon questions
Which files are supported?
Import CSV, XLS and XLSX files. Export lead data as CSV or XLSX. Contact person, location, notes and an alternative phone-number column are optional.
What should I check if an import fails?
Check the header row and the required company-name and phone-number mappings, including any automatic suggestions. Start by sending support the file format and error message, not your complete lead list.
Why are no start times available?
Check the date, duration, working hours and buffer under Appointment availability. Existing Callstack plans and permitted device calendar events may occupy time; all-day events do not block slots.
Why is there no reminder or app-icon number?
Check the main switch, the individual reminder settings and system permissions. Focus and battery-saving settings may affect delivery. On Android, numeric badges for overdue tasks depend on the launcher and are not available on every device.
Where are my data and backups stored?
Lead data is stored locally on your device. You can create a JSON backup in settings. Store it securely: the trial counter is encrypted and backups are checked for tampering, but lead contents are not fully encrypted.