The first step toward adopting a tougher code of ethics for the House was taken yesterday. A commission task force approved proposals ranging from a limit of 15 per cent of salary on members' outside income to an abolition of lame duck travel and an end to unofficial office accounts.

The full commission, which is made up of House members and citizens and officially called the Committee on Administrative Review, will act on the proposals next Monday. After review by a regular House committee, they are expected to reach the House floor - and further debate - in March.

In addition to the proposals on outside income, travel and office accounts, the task force also approved:

Requiring fuller disclosure of income, gifts, reimbursements, holdings, debts, securities, transactions and real estate by both the member and the spouse. The disclosure requirments would apply to candidates as well as members and a penalty of one year in prison or $10,000 fine would be levied for falsification or failure to disclose.

A ban on accepting any gift over $100 in any year from one person or organization or corporation having an interest in legislation or from foreign nationals.

Prohibitions on lame-duck travel by members defeated for re-election and on "double dipping," where members claim a per diem when their expenses have already been covered by counterpart funds or other sources.

Curbs on the use of the free franking privilege for mail.

Each of the proposals was designed to end an abuse or curb a questionable practice that many feel have contributed to Congress' poor public image.

For instance, though each House member is given an average of about $50,000 a year in taxpayers' money for official office expenses and allowances, many members have "unofficial off ice accounts" funded by "contributions from lobbyists, friends or left over campaign funds.

Though official expenses must be accounted for, the commission points out that "there are no regulations, including no disclosure requirements, regarding unofficial accounts, their amounts, their sources of contributions or their uses."

Recently it was revealed that Rep. John McFall (D-Calif.) received $4,000 in such "contributions" from South Dorean businessman Tongsun Park for his "unofficial office account." He sand dollars from eight Washington lobbyists for the air transportation industry (McFall is chairman of the appropriations subcommittee on transportations), the California wine institue and other interests. McFall said the account was used not only to pay office and political expenses but to make interest-free loans to himself and staff, which he said were repaid to the fund.

Rep. David Obey (D-Wis.), chairman of the 15-member commission, said yesterday an estimated 150 House members have or did have such accounts, which average about $5,000 a year but can go up to $23,000.

Because of the "potential for abuse," the task force recommended abolishing unofficial office accounts effective next Jan. 3.

Along the same line, the task force recommended that proceeds of testimonials to raise campaign funds could not be converted to private use. It was recently revealed that House Majority Leader Jim Wright (Tex.) used the proceeds of a 1976 testimonial to pay off personal debts as well as campaign expenses.

The adoption of proposals in six different areas by the task force headed by Rep. Lee Hamlton (D-Ind.) was only the first stage in a long process of writing a new code.

Adoption by the full house would make the proposals part of the House Rules, but they would then be turned over to a special committee headed by Rep. Richardson Preyer (D-N.C.), so that they can be made unform with any proposals the Senate might adopt and can be turned into law.

A controversy is expected over the proposal that outside earned income, including honoraria from speeches, should not exceed 15 per cent of a member's salary and honoraria should be limited to $500 an appearance. No limit on investment income is proposed, though it would have to be disclosed.

Currently there is no limit on outside earned income, and limits of $2,000 per speech and $25,000 aggregate on honoraria.

Under the present salary of $44,600, a member would be limited to making $51,500 a year. The proposed salary increase to $57,500 would lift the limit to $66,125 a year in total earned income.

The rationale for the limit is that it "assures the public that members are not cashing in on their positions of influence and outside activities are not detracting from the member's attention to his or her job," according to the task force report.

Depending on how House members respond, "there may have to be some adjustments before we go to the commission," Obey said. His commission - appointed by former Speaker Carl Albert last summer in the wake of congressional sex, payroll and expense account scandals - consists of eight House members and seven from business, labor, public interest and academic groups.

Obey said the package represented a "good approach, a tough approach. With the strong support of passage."

Speaker Thomas P. O'Neil Jr. (Mass.) has announced his intention to have the toughest code of ethics of any legislature in the country, and the commission on federal pay raises has recommended that any pay raise granted to Congress be tied to adoption of a tougher code.