The Financial Services Authority, police, Customs & Excise and trading standards officers are using a wide range of historical laws in addition to the Regulation of Investigatory Powers (RIP) Act to apply for communications data.
ISPs are concerned they lack the expertise and resources to deal with interception requests under such a wide range of different legislation.
"We would like it to be much simpler so everyone comes through the same channels," Clive Feather, Internet expert at service provider Thus, told MPs.
Although large ISPs can afford their own legal teams to vet requests, smaller ISPs may not have the legal expertise to challenge requests that fall outside the law.
ISPs are also concerned that the historical laws fall outside the safeguards of RIP Act codes of conduct or the protection of the Government's Interception Commission.