How long can I work in Bulgaria as a seasonal worker?

Bulgaria runs two seasonal-work tracks. For work of up to 90 days within a 12-month period, the employer handles a registration/declaration process and no residence permit is needed. For longer engagements, more than 90 days and up to nine months, you apply for a seasonal worker residence permit.

The nine-month figure is a cap within a 12-month period, reflecting that this is genuinely seasonal rather than permanent employment. If your work will run longer or become ongoing, the seasonal route is not the right fit and you should look at the single permit instead.