Nurhussein was granted asylum but Mohammed, who came into Britain via a refugee camp in Calais in 2008, was refused leave to remain and lived in the UK illegally.
Nurhussein was previously jailed in 2012 for robbery using an imitation handgun.
Prosecutor Alistair Richardson said the defendants became “deeply radical” and had supported Isis in whatever ways they could.
He told the court: “They wished to travel to Isis territory to join them. From the UK, the two of them, together, offered their support financially.
“They arranged for the provision of, and provided funds for, their mujahideen, or fighter, brothers, who remained in Iraq fighting for that organisation.”
Mr Richardson said Wassim arranged for a go-between in Denmark to enable money to be sent to Isis with “no problems”.
On 20 April 2019, a transaction of £1,300 was made from an account in Manchester to a Western Union bank branch in Copenhagen.
A second transaction of £599 was made by Nurhussein on 5 June to the same bank and on 2 July the process was repeated for a further £800.
Counter-terror police started an investigation in 2018 and arrested the pair in coordinated raids on 16 July last year, where mobile phones and other evidence were seized.
Commander Richard Smith, head of the Metropolitan Police Counter Terrorism Command, said: “The Met works with other police forces and security services to provide a counter terrorism network, both at home and abroad, whose strength and effect is continually felt by those who conspire to commit acts of violence and terror.”
Additional reporting by PA