Around 40,000 SMEs are due to reach their auto enrolment stage date this year as all companies employing between 60 and 500 people will be taken into the scheme across 2014.
In the first instance, employers have to make a minimum contribution of 1% to employee pensions with that rising to 3% by 2018.
But Donald Fleming, head of pensions for KPMG in Scotland, said: "We've already heard anecdotal evidence from a number of suppliers who say that they won't consider putting themselves forward for business unless an SME has come to them at least three months ahead of their staging date.
"The inference is clear - if your business does not take planning seriously it may struggle to find a pension supplier suitable for your business.
"If the arrangement is not set up in time this could leave the company in breach of its statutory requirements, while staff will miss out on the intended benefits."
Any company found in breach of the requirement could face a range of punishments from The Pensions Regulator.
That ranges from a £400 initial penalty up to daily fines of between £50 and £10,000 for continually failing to comply.
Mr Fleming added: "If they have not done so already, SMEs need to consider elevating auto enrolment as a board room priority."