Senior MPs have called on the Home Office to urgently lower fees faced by those seeking access to asylum, immigration, nationality and customs services.
The Guardian reports the department made profits of up to 800% on some applications from families, who often faced thousands of pounds in costs.
The call comes as the independent chief inspector of borders and immigration, David Bolt, launches an inquiry into the rationale of the sky-high charges.
The paper found that while in 2011 the fee for adult naturalisation was £700, it has since shot up to £1,330.
The cost of a settlement visa for a dependent relative has risen from £585 in 2008-09 to £3,250 in 2017-18, an increase of 450%.
Meanwhile it costs £1,012 to register under-18s, up from £500 in 2011.
Yvette Cooper, chair of the Home Affairs Select Committee, said of the fees: “The scale of citizenship fees for many people, especially children, who have lived here for many years, has become a real and growing problem.
“Under the current system, children can be left in a precarious position, unable to study, work or access social security at the end of their teenage years.”
The issue comes hot on the heels of the Windrush scandal, where a number of migrants who came to the UK from the Caribbean before 1971 faced deportation threats and lost access to public services.
Stephen Doughty, a Labour MP who also sits on the committee, said: “Given the repeated shambles in the Home Office over a series of immigration processes, let alone the widening scandal over highly skilled migrants, many people will rightly ask whether the Home Office provides value for money to individual citizens and applicants.
“Fees and charges being made by the Home Office should be reviewed. It is never acceptable for them to make a profit on these crucial activities.”
Chai Patel of the Joint Council for the Welfare of Immigrants said it was “simply wrong” that children in the UK entitled to British citizenship are deprived of it due to cost.
“Instead, they are either forced into irregular status, or forced into a vicious cycle of paying the slightly less expensive fees for temporary status, over and over again, never quite accumulating enough to register as British,” he said.
A Home Office spokesperson said: “When setting fees, we also take into account the wider costs involved in running our border, immigration and citizenship system, so that those who directly benefit from it contribute to its funding.
“There are exceptions to application fees to protect the most vulnerable, such as for young people who are in the care of a local authority.
“Application fees are also waived where evidence provided shows that a person may be destitute, or where there are exceptional financial circumstances, and requiring a payment would result in a breach of rights under the European convention on human rights.”
Bolt will look at “the rationale and authority for particular charges, including the amounts charged”. He is seeking contributions from regular stakeholders and anyone with first-hand experience of the Home Office charges by 16 July.