The UK said the decision to suspend the service is for the safety of customers.
Wak-in service for visa applicants has been suspended by the United Kingdom.
The Flexi Appointment service suspension, however is a temporary measure, according to the UK government.
The service allows the submission of applications during the opening hours of the visa application centre (VAC) or before and after the applicant’s scheduled appointment date.
This was disclosed in a statement issued on Monday January 10.
The UK said the decision to suspend the service is for the safety of customers.
The statement reads: "To protect the safety of customers waiting outside of our Visa Application Centres, the Flexi Appointment (walk-in) service has been temporarily suspended. You will not be able to book one of these appointments online or by turning up at the VAC.
"If you have already paid for this service (before 10 January) then you can still benefit from this.
"You should not attend the VAC until it is your allocated appointment time, or you have been contacted by TLS to collect your passport.
"Visa customers who turn up at the VAC significantly before their appointment will be asked to leave and return at the correct date and time.
"Where there are extremely compassionate or compelling circumstances (for example, medical emergency), UKVI may consider expediting specific cases.
"However, the bar for this is high and will be assessed on a case-by-case basis. If your request is exceptionally urgent you can contact UK Visas and Immigration for help. Please note that this is a chargeable service for overseas customers.
"If you have not yet been contacted by TLS, this means your application is still being processed by the UKVI team and the VAC will not be able to assist you.
"The staff in the VACs are not involved in the processing of UK visa decisions and are unable to provide updates on your application."
The UK added that it was working on scheduling more appointments in order to address the large number of applications on student visas.
"We are aware that large numbers of prospective students are queuing outside of the Visa Application Centre (VAC) to try and secure a visa appointment," the statement reads.