Sen. Herman E. Talmadge's 1974 campaign committee reimbursed him for personal expenses that should not have been paid out of campaign funds, Talmadge's tax accountant said yesterday.

Testifying before the Senate Select Committee on Ethics, the accountant, Lawrence W. Earls, said he informed Talmadge's financial secretary, Allyne Tisdale, in early 1975 that some of the Georgia Democrat's campaign expense claims were not reimbursable.

Nevertheless, Talmadge received the full $26,912 he claimed he spent out of his own pocket during the 1973-74 campaign. The payments were made by the Talmadge Campaign Committee, which Tisdale served as bookkeeper.

One of the five formal charges against Talmadge that the Ethics Committee is investigating is that reports of receipts and expenditures which the Talmadge Campaign Committee filed with the secretary of the Senate were false.

Talmadge lebeled the charge "minor" in his opening statement to the ethics hearing two weeks ago. He said he had reported the $26.912 reimbursement for his campaign expenses in his 1975 report to the secretary of the Senate.

In his statement, however, Talmadge did not deal with the possibility that some of the claimed out-of-pocket expenses might not have been valid.

Earls, a tax partner in the national accounting firm of Peat, Marwick and Mitchell, told the ethics panel yesterday that he began handling Talmadge's financial affairs in 1972.

In early 1975, he said, Tisdale called him to discuss possible taxes on the campaign reimbursements. Committee counsel Douglas McCullough asked Earls whether he made any determination during their conversation whether the expense claims were reimbursable.

Earls gave the committee a somewhat confusing response, using the word "contribution" where he apparently meant "expenditure". But in any case, he indicated that he told Tisdale that he did not see how some of the claimed expenses "would be reimbursable by the campaign committee."

Earls declined to elaborate after the session. But his attorney, James Kennedy, emphasized that Earls was not speaking of all of the expense claims Talmadge submitted.

Earls also told the Ethics Committee that in 1977, during a deposition taken of him as part of Talmadge's divorce, he learned that Talmadge had allegedly received thousands of dollars in Senate payments for false office expense claims. But he said he did not discuss the matter with Talmadge until it came up in news reports nine months later.

Talmadge has also been accused of filing false office expense claims with the Senate.He denied under oath last year in secret testimony to the Ethics Committee that he know about the false expense claims until June of 1978 and blamed the claims on his staff.

In his testimony yesterday, Earls did not explain the delay in discussing the false claims with Talmadge. According to court documents, Talmadge also learned about the Senate over-reimbursements during the divorce proceedings in 1977. He has not publicly discussed the discrepancy about when he first learned of the overpayments.

Earls appeared only briefly yesterday day before the committee, which is in its third week of testimony on the Talmadge case. The accountant is scheduled to be questioned again when the hearing resumes today. CAPTION: Picture, Attorney James Hamilton and Sen. Talmadge confer before hearing, by James K. W. Atherton-The Washington Post