A new mandate from the Massachusetts Department of Revenue that went into effect on Nov. 1 shakes up the process of transferring high-value properties and adds steps — and costs — for non-resident sellers.

The rule mandates that withholding agents, like attorneys, escrow companies or title companies, must collect and send a required monetary withholding and file a return for all transfers or sales of properties costing $1 million or more.

The withholding amount is determined by the personal income tax due on the net gain from a non-resident’s sale or exchange of the property.

For transactions grossing $1 million and over, each seller must complete a Transferor’s Certification. The agent will use the information from these documents to create a return filed with the DOR. Notably, the form and the return are required even in cases when no withholding is collected.

The law includes exceptions for foreclosures, properties located on Commonwealth borders and sales involving payment of the seller’s debts secured by a mortgage.