The U.S. Senate may be the world's most exclusive club, as is often claimed, but for perquisites, it seems Franciscan when compared to the House.

Different formulas are used to compute the office-operation allowances for senators and members of the House, but the biggest difference is the way in which they are allowed to spend their money.

More lenient rules allow House members to pay for many perquisites prohibited by Senate rules.

For example, House members can pay as much for food and lodging as they wish, or entertain as many constituents as they wish, wherever and whenever they wish, as long as they stay within their annual allowances.

Senators and their staff traveling outside of Washington collect $50 a day to cover food and lodging In Washington, no food or lodging can be charged as official expense.

Nor can senators or their employes use their office accounts to entertain visitors. Even using their $50 per diem, senators must certify that food and lodging expenses were theirs alone.

Like members of the House, senators and their aides may collect mileage for travel in private autos and they can lease cars on a day-by-day basis for official travel. But unlike the House, the Senate bans fulltime leasing of cars for statewide use.

Senators and House members have use of the frank for official mail. But unlike House members, senators are limited in the number of stamps they can purchase for use on special mailings.