The ICO was responding to a complaint alleging that St Mungo’s had handed over information about rough sleepers to the Home Office without their consent, putting them at risk of deportation.
But the information watchdog found that between 2010 and 2017 the personal data of some people might have been processed without their consent – but it add that might may have been in the public interest, as defined by the DPA.
The ICO concluded that the charity’s existing information rights practices did not raise any concerns.
In a statement, St Mungo’s said: "Our policy is that we do not share information about individuals with the Home Office, except when an individual has given their consent, or in situations where people are at significant risk to themselves or someone else.
"We take complaints seriously and are finalising an internal review into St Mungo’s data-sharing policies in relation to non-UK nationals over some years prior to 2017."
The charity also said it had not accompanied immigration compliance and enforcement officers on shifts since the High Court ruled last year that Home Office policy on the removal of European Economic Area nationals for sleeping rough was unlawful.
Non-UK nationals were at risk of being left without support or housing because they might not be entitled to benefits, the charity said.
It also said it often worked with people to help resolve problems with their immigration status, which could mean sharing information with the Home Office with the person’s permission.
"St Mungo’s is currently providing a safe place to stay for 50 people who have no access to help in the UK," the statement said.
"We hope to expand our capacity to help more. People in this situation would otherwise be sleeping rough while decisions on their immigration status and entitlements are resolved."
The ICO said it would take no further regulatory action over the concerns.