What is §613a BGB and why does it matter in German M&A?

§613a BGB governs the automatic transfer of employees on a transfer of business (Betriebsübergang) — most relevant in asset deals (in a share deal the employer entity is unchanged, so §613a isn't triggered). When a business or part of a business transfers, the affected employees pass automatically to the acquirer on their existing terms and conditions, which generally can't be worsened for one year after the transfer. Employees must be informed in writing of the transfer and its consequences, and each has the right to object (Widerspruchsrecht) within one month — if they object, they stay with the seller (risk: key talent opts out, or stays behind as a cost). Dismissals 'because of' the transfer are void. The practical implications for a deal: it shapes asset-vs-share structuring, you can't freely restructure the workforce around the deal, the information/timing requirements must be met (defective notice extends the objection right), and headcount/restructuring plans (and any Sozialplan) must account for it. It's a core German labour-law constraint on deal structuring.