The City must choose which rights its financial services sector actually needs, and which are just nice to have, before it gets to the Brexit negotiating table.
The report by Open Europe stresses that the passporting regime does not consist of one set of rights and those involved in the Brexit talks should therefore focus on securing rights for firms which need them the most, and potentially stop fight for those which are less important.
In particular, the researchers noted the banking sector, especially wholesale and investment divisions, was highly dependent on passporting. The report estimated around a fifth of annual revenue in the industry was tied to passporting rights.
However, Open Europe found asset managers were less dependant on passports being in place, as many had already set up subsidiaries elsewhere in Europe to overcome other regulatory hurdles. The report estimated that at most seven per cent of assets managed in the UK would be under threat if passporting was lost.
"The significance of the financial services passport depends on the industry," said Open Europe's senior policy analyst Vincenzo Scarpetta. "It is important to business in some sectors, but has much less value in others.
"To claim that the success of the UK as a global financial centre is entirely reliant on the passport is exaggerated.
"In the upcoming negotiations with the EU, the government needs to focus its efforts on retaining or replicating a passport-like relationship in those sectors where it is most valuable."
Recent figures from the Financial Conduct Authority show almost 13,500 firms rely on passporting rights to do business from their UK base into other EEA markets and vice versa. However, of those firms, just over 8,000 use passporting to access the UK market from elsewhere in the EEA.
Scarpetta added: "It is not obvious that business moving out of the UK would relocate to another European hub: New York, Singapore or Hong Kong would be just as well, if not better, placed to reap the benefits – meaning Europe as a whole could end up worse off."