LONDON-- Royal Bank of Scotland Group PLC confirmed Thursday that it would re-domicile its holding company to England should Scotland vote for independence in a referendum next week.

The 80%-government owned bank said "there are a number of material uncertainties arising from the Scottish referendum vote which could have a bearing on the bank's credit ratings, and the fiscal, monetary, legal and regulatory landscape to which it is subject."

"The vote on independence is a matter for the Scottish people. Scotland has been RBS's home since 1727. RBS intends to retain a significant level of its operations and employment in Scotland to support its customers there and the activities of the whole bank," it said.

Late Wednesday, Lloyds Banking Group PLC said it would move its legal headquarters to London from Edinburgh in the event of a "yes" vote for Scottish independence on Sept. 18.

Lloyds, which is 25% owned by the U.K. government, said in a statement it had received an increased level of enquiries from customers about its plans after the vote. "While the scale of potential change is currently unclear, we have contingency plans in place which include the establishment of new principal legal entities in England," the bank said.

On Wednesday, Standard Life PLC also effectively ruled out keeping its main business in an independent Scotland.

The insurer and fund manager said that in the event of a "yes" vote to independence, it would ensure that all of its non-Scottish U.K. customers would continue to be covered by Britain's main financial regulator, the Financial Conduct Authority, and the U.K.'s Financial Services Compensation Scheme. That means that it would have to transfer most of its funds out of Scotland and re-register them in the rest of the U.K. About 90% of its customers aren't based in Scotland.

Scots will vote Sept. 18 on whether to go it alone as an independent country or stay in a union with England and Wales that has lasted more than 300 years. The U.K. also includes Northern Ireland.

Write to Ian Walker at ian.walker@wsj.com

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