There will be no appeal of the 15-year sentence for a New Zealand man who was set-up as a drug mule via an online romance.

Antony de Malmanche's lawyers flagged a possible appeal at the verdict last month.

But Bali's district court says it didn't receive notice by the deadline and has declared the sentence final.

Spokesman Hasoloan Sianturi says the prosecution, which had recommended 18 years' jail for the 53-year-old, then withdrew its appeal.

"With this, the sentence for the convict de Malmanche ... has been declared final," he said.

"So far, we haven't accepted an appeal request from the convict nor his lawyer either."

Ashari Kurniawan, spokesman for Bali provincial prosecutors, says the appeal was withdrawn because the 15-year term exceeded two-thirds of what it had sought.

"There's no obligation for us to ask for appeal," he said.

De Malmanche says he didn't know there was 1.7kg of methamphetamine in his backpack when he arrived in Bali on December 1 last year.

The Whanganui man claims he planned to meet a woman he had fallen in love with online, Jessy Smith.

His trial saw pages of chat logs with "Jessy" and heard expert testimony that de Malmanche's low IQ and mental illness made him particularly susceptible to brainwashing.

An appeal could have seen the sentence increased to the death penalty.

Indonesian President Joko Widodo is enforcing capital punishment for drug offenders, believing his country to be gripped by a narcotics emergency.

De Malmanche is serving his time in Bali's Kerobokan jail, once home to the two Australians executed for drug offences in April, Andrew Chan and Myuran Sukumaran.