Following issues with the deployment of Government eVisas, the Home Office has stated that airlines will continue to accept passengers with expired UK resident permits until "at least March 31."
Digital eVisas are replacing physical biometric residence permits (BRP), which serve as documentation of an individual's eligibility to live, work, and receive benefits in the United Kingdom.
The use of the outdated documents was to end on December 31.
But the full rollout is being postponed after campaigners warned problems with the system could “lead to another Windrush”.
Over six million people are already using eVisas and a further 3.1million have applied since the changeover was announced, the Home Office said on Wednesday.
But the Government refused to confirm how many people were still waiting to switch over to the new digital system.
Migration Minister Seema Malhotra said creating an online UK Visas and Immigration (UKVI) account "has been more difficult for a small proportion" of people, for example those who have lost their BRP and have no other form of identity document.
"We have already made changes to improve the process for these customers, including creating UKVI accounts automatically for newly recognised refugees since November 1,” she said in a written statement to the Commons.
"But we remain concerned that some of the risks of the rollout, particularly to those making the transition from BRPs and legacy documents, were not clearly identified and managed under the previous administration and have been consulting stakeholders on other issues raised by them, along with the wider concern that this change could lead to another Windrush.”
Ms Malhotra added: “In order to smooth the transition to eVisas, we have decided to allow carriers to accept a BRP or EUSS BRC [EU Settlement Scheme biometric residence card] expiring on or after December 31, 2024 as valid evidence of permission to travel until at least March 31 and this date will be kept under review.
“Customers travelling in the early part of the year are therefore advised to continue carrying their expired BRP, as this will add to the range of checking options already available to carriers.”
Passengers will remain subject to the “usual immigration checks and requirements” and anyone seeking to enter the UK whose underlying immigration status has expired will be liable for refusal of entry, the Home Office said.
The department encouraged anyone who has not yet accessed their eVisa to still apply before the end of December.
The proposals were first announced in April, under the previous Tory administration, and were designed to ensure greater control “over who comes here to live, work or study, strengthening border security and preventing abuse of the immigration system”.
But there has been multiple complaints from people who have failed to gain access to the new digital system, sparking fears that people could be left stranded abroad because of IT glitches.
Some £4million was earmarked to support organisations to help vulnerable people who may struggle to obtain an eVisa without assistance.
There were also concerns the rollout was due to take place on New Years Day - a bank holiday - meaning immediate problems would be harder to address.
Foreign nationals with “leave to remain” who are placed on “3C leave” were said to particularly prone to getting error messages while trying to generate an eVisa.
Their rights to work, study or claim benefits in the UK are protected while their claim is assessed, but many employers and landlords insist on seeing a physical document confirming their status.