Barclays is closing around 100 UK accounts held by cash transfer businesses after fears emerged they could be being used for money laundering purposes.
Aid workers have told BBC News the service is a lifeline for 40 per cent of the Somali population who rely on the transfers.
Expatriates from the African nation send remittances back home, but the banking facilities in the country have collapsed.
Barclays is the last major UK institution that provides such money transfer services to Somalia.
The largest businesses of this kind in the region is Dahabshiil and it said Barclays has given them a temporary reprieve of one month.
It claims it is now urgently trying to meet the bank's criteria to keep the account open.
Should Barclays remove the service is is feared the cash transfer business would go underground.
Abdirashid Duale, chief executive officer of Dahabshiil, told the news provider the bank's decision could see transfers put into the hands of "unregulated and illegal providers".
By Tony Aynsley