The upper house of the Swiss parliament has voted to double the tax base from wealthy foreigners under the lump sum taxation regime.

If approved by the lower house, the revenue from the 4,500 foreigners who pay lump sum tax will be increased across all cantons that allow it. In total, it is estimated to jump from SFr130 million ($141.5 million) to SFr255 million. Supporters of lump sum taxation are generally supportive of the change as it would keep the system alive, a spokesperson for the Swiss parliament told this publication.

Thirty-five members of the upper chamber voted in favour of the proposal, five abstained and no one voted against it.

The next step in the parliamentary process is the lower house, where the issue is likely to be heavily debated as Switzerland’s Socialist Party, which has a stronger presence in this chamber, is against the legislation because it wants to abolish lump sum taxation altogether.

The lump sum system means that wealthy foreigners who move to Switzerland have the opportunity to negotiate their tax based on their expenses rather than income. If they opt for the system, they are not allowed to work nor do business in the country.

Vaud is the canton with most people under the “special regime”, with over 1,000 such cases. There are still 141 people on lump sum tax in Zurich, where it was abolished after a referendum in 2009, but they still pay lump sum tax at the federal level.

“For someone relocating from abroad, there are indefinite opportunities for tax planning in Switzerland,” Hugues Salomé, partner in charge of tax consulting for private clients at PwC in Geneva and Lausanne, has previously told WealthBriefing. “The lump sum taxation is one alternative, but it is not the only ‘trick’. You can also restructure your assets with sophisticated tax planning or place them in a trust, using differences in tax regimes among countries. ”

Salomé has also suggested that imposing a minimum tax base for the regime would be a good way of satisfying those who want to abolish the system.

Tim Urquhart, solicitor, consultant and founding member of LS&S GmbH, a Swiss private wealth law firm which is part of the Hawksford Group, has told this publication that he usually advises clients to pay full taxation so they can run a business and receive protection in terms of wealth tax and succession tax.