Simon Forrester, chief executive of the British Pest Control Association (BPCA), believes the move will have a big impact on businesses that carry out their own pest control or use professional contractors.
He said: "Laws governing the use of certain pesticides are changing and farmers who use them need to be well aware.
"Tighter controls come into force next summer and those who intend to keep pest control in-house must take action.
"They will need qualifications to show they can use these products responsibly or be on an approved assurance scheme.
"Those who pay professional contractors to carry out the work must also ensure the company has the right credentials.
"The new legislation will affect a lot of people and they'll need to get their house in order in plenty of time. The deadline is set in stone and those who leave it too late could create serious problems for themselves."
The use of specialist poisons known as Anticoagulant Rodenticides (ARs) has come under increasing scrutiny in recent years after evidence of secondary poisoning.
The edible baits are used by pest control contractors, growers, farmers, small holders and gamekeepers as the principal control measure for rodents throughout the UK.
Forrester added: "The problem is the products are non-specific, which means that while they kill targeted pests, they can also kill other animals that prey on them.
"The toxin is passed down the food chain, which leads to secondary poisoning.
"The levels of ARs present in non-target species such as barn owls, kestrels and red kites has been increasing for a number of years and the authorities demanded corrective action."
The pest control industry has now set up a stewardship scheme, co-ordinated by the Campaign for Responsible Rodenticide Use, to control and monitor the use of the products.
Forrester said: "ARs will remain on the market if we use them properly, but the way they are used needs to change and the legislation is designed to ensure this happens."
Anyone using the products must hold a certificate of competence which proves they have received proper training and prove their knowledge is up to date, or be on a farm assurance scheme approved by CRRU.
Forrester added: "For the first time, it will become an offence to buy or use these products without having the proper credentials in place.
"If someone is found to have done so, the fault will be their own as the 'user' and their employer could also be held responsible.
"The legislation also applies to contractors, so farmers could still be liable to prosecution if they use an unqualified pest controller."
Growers keen to continue their own pest management can earn the recognised qualification through the BPCA.Forrester said: "Our membership criteria insists that every company or individual technician must already hold Level Two in Pest Management, the industry standard qualification.
"It means they are already experts in the field and qualified to apply all kinds of specialist pesticides, including SGARs. They must also take part in a recognised CPD scheme such as those organised by BASIS PROMPT.
"So people who use members of the BPCA have peace of mind that the job is being done both professionally and lawfully."
Visit www.bpca.org.uk for more details.