Cash-strapped businesses have said they may not be able to stay afloat long enough to apply for grants of £25,000, which open for application on Monday.
Economy Minister Diane Dodds announced the process of applying for the loans for retail, hospitality and tourism firms, with applications taking 15 business days to process.
The Minister also extended the £10,000 grant scheme to small industrial businesses.
Retail NI chief executive Glyn Roberts said the £25,000 scheme was being launched much later than had been expected. The Northern Ireland Tourism Alliance has also said operators may not be able to remain in business long enough to apply.
Mr Roberts said: "While it is welcome that we have clarity on a start date for the £25k grants, we are concerned that many cash-strapped businesses may not survive until they receive the payment early next month.
"Many businesses also assumed that they would get the grant well before then to keep them going until they receive furlough payments.
"The £10k and £25k small business grants also need to be altered to support those companies with multiple premises rather than just a single payment."
Ken Sharpe, the owner of two restaurants in Co Down, has said he may not able to able to continue paying staff, even in part, as he waits for assistance.
Already, he said he was paying some staff a percentage of their wages.
Mr Roberts also urged the Executive to extend a holiday on business rates from three months to 12 months, as is the case in the rest of the UK.
"Again, we believe this should be targeted to businesses that need urgent assistance," he said.
Meanwhile, Mr Sharpe, who owns The Salty Hotel and Bistro in Bangor, as well as the town's Boat House restaurant, said he felt there had been little clarity about when government help would arrive.
Applications under the Chancellor's UK-wide job retention scheme open on April 20, the same day as applications to Northern Ireland's £25,000 grant scheme.
After examining his cash reserves and cashflow at the outset of the crisis, he said it was clear he could not even pay staff 80% of their wages - the percentage which government has said it will refund under its job retention scheme. He has nearly 50 staff and says he has reached an agreement to only pay 50% of wages to some.
Mr Sharpe added: "I haven't even been able to pay very understanding suppliers but now with the applications for assistance not opening until April 20, five weeks after the promise from the Prime Minister of 'immediate' support, I am sitting here at Easter while Stormont executives enjoy the Bank Holiday weekend, staring at my cashflow forecast like staring into an abyss.
"I have no idea how I am going to be able to pay my staff anything for the last two weeks of April so I would appeal to our elected representatives to help my staff as they fight to keep a roof over their heads."
The Small Business Support Grant Scheme has now paid £10,000 out to over 14,000 small businesses. Now it's also been extended to 2,500 small firms which benefit from industrial de-rating. Minister Dodds has said it's aimed at supporting up to 27,000 businesses.
Both measures, the £25k scheme and the £10,000 Small Business Grant Scheme, close for applications on May 20.