The 96-year-old head of the Privy Council has been appointed as temporary regent in the stead of the proclaimed heir, Crown Prince Maha Vajiralongkorn.
The appointment comes as Thailand's tourism industry starts to feel the effects of a mourning period for King Bhumibol Adulyadeiei.
The famous Khao San Road is normally bustling with tourists but now the streets are empty.
Tourists are frustrated with the closure of pubs and nightclubs.
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"We went from one night full of party, the next night we were on the beach ready for a party and it was completely shut up shop and now you can't drink of the street or nothing and you can't buy drinks in the supermarket and there's literally no music no lights nothing anywhere," one British tourist told SBS News.
Bangkok's famous red light district is normally filled with tourists everyday but out of respect for the Thai King all businesses have completely shutdown.
Those who bought tickets to upcoming concerts are being given refunds.
Hotelier Jarupa Sunthonpagsit said she was already fielding calls about cancellations but was trying to stay positive.
"What I'm trying to do is change the plan to take them to the temple instead so we try to figure out what we can do instead of like the party or something we shouldn't do at this time," Ms Sunthonpagsit told SBS News.
American tourist Carly Pethick told SBS News she was thinking about leaving Bangkok early.
"We've been I guess a little bit hesitant to go to some of the more popular areas again the uncertainty of the politics and everything," she said.
"It hasn't really stopped us from doing anything yet but it almost, we're not sure, we want to keep an eye, we might exit the city a little bit earlier then expected."
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Local couples who planned to get married have had to postpone their reception parties. Bride and groom Junlapat and Kanjira Bunditput said they were disappointed but couldn't complain.
"We prepared everything but we called it off at the last minute," they told SBS News.
"Everybody understands the situation. It didn't take us long to cancel our reception."
The government is hoping the mourning period won't impact the long term health of the economy.
Last night, thousands of people gathered at Dhammakaya temple just outside Bangkok to pray for the late King.
It's the only Buddhist temple in Thailand open for prays 24 hours a day.
Mourner Kaniaya Tusanasarit said people had travelled from across Asia to pay their respects.
"This is not for our King, for world peace, for everyone in Thailand and we need everyone to do the good thing for our King," she said.
Outside the Grand Palace mourners continue to gather. Palace officials have been letting people in so they can perform funeral rituals for the man who was their King for seven decades. But many have to sleep overnight if they want to be first in line.
Volunteer Silin Wit-Tiyanuparbyuenyong has been making black ribbons for people who can't afford to buy black clothes.
"I'm here at Sanam Luang to sew black ribbons to give to people who don't have black shirts to wear so they can honour the King as well," she said.
