Do I lose my seniority for shift-bidding purposes if the business changes hands?

Your underlying length of service doesn't legally reset just because the business was sold and you kept working — Ontario law treats your employment as continuous in that situation, which is what protects statutory entitlements tied to service, like vacation and notice. But shift-bidding seniority specifically is usually a workplace-policy, or in a unionized workplace a collective-agreement, concept — not something the Employment Standards Act, 2000 defines or guarantees on its own.

That means a new owner isn't legally forced to run shift bidding exactly the way the old employer did, or to weigh your accumulated seniority the same way, unless a collective agreement or an assumed policy specifically requires it. In practice, many buyers do carry forward existing seniority lists because it's simpler and keeps staff happy, but it isn't automatic the way statutory entitlements are.

If you're in a union, your bargaining agent should be able to tell you exactly how seniority is handled through the sale under your collective agreement. If you're not unionized, ask the new owner directly whether shift-bidding seniority is being preserved, since this is genuinely something a buyer could choose to change.