Sentencing for the offences is due to be given at Birmingham Crown Court on 13 July.
The company still faces other charges in a separate regional court over the same incident.
Last year the company was forced to recall about one million chocolate bars after 37 people fell sick across the country due to salmonella.
Cadbury's failure at the time to follow new EU-wide hygiene rules, known as Hazard Analysis and Critical Control Point (HACCP) analysis, serves as a warning to other processors who may also have been tardy in making sure the system is in place at all their plants.
In April this year the Birmingham City Council decided to bring the company to court for the incident, alleging the company knew about the contamination but still put the products on the market.
"Mistakenly, we did not believe that there was a threat to health and thus any requirement to report the incident to the authorities," Cadbury said in a statement today.
"We accept that this approach was incorrect.
Quality has always been at the heart of our business, but the process we followed in the UK in this instance was unacceptable.
We have apologised for this and do so again today."
The company said it has spent about £20m since last year on "new and rigorous" quality control procedures.
"The processes that led to this failure ceased from June last year and will never be reinstated," the company pledged.
In related news the Hereford Council today brought charges against Cadbury relating to the same incident and the operations at the company's factory at Marlbrook.
Cadbury said it is examining the new charges and would respond at the appropriate time.
A hearing is set for 24 July.
"We sincerely regret this lapse and are focused on ensuring that this can never happen again," the company stated.
"A major review has taken place of our quality, health and safety procedures globally to learn lessons and ensure that our consumers can rely on the highest levels of processes and standards wherever we operate."
The court action targets the company's alleged failure to report to food regulators that its private testing in January last year had found a rare Salmonella strain in the chocolate products.
The products were on the market until June, when the Food Standards Agency revealed some people had fallen sick from the chocolates.
Cadbury then withdrew the seven chocolate products from the UK market The Birmingham City Council court action relates to three offences.
The first charge accuses Cadbury of being in contravention of the General Food Regulations 2004.
The council alleges that, between January 19 and March 10 Cadbury "placed on the market ready-to-eat chocolate products which were unsafe, in that they were injurious to health and unfit for human consumption due to the presence of Salmonella organisms".
The second charge alleged that Cadbury "failed to immediately inform the competent authorities that they had reason to believe that ready-to-eat chocolate products, placed on the market, may be injurious to human health due to the presence of Salmonella organisms".
The third charge alleged that the company also "failed to identify hazards from ready-to-eat chocolate products contaminated with Salmonella and failed to identify critical control points and corrective actions in line with HACCP(Hazard Analysis and Critical Control Points) principles".
Each offence carries a maximum penalty of an unlimited fine and up to two years of imprisonment for managers identified as causing the problem, the council said.
The contamination was traced to a leaking waste water pipe at the company's plant in Marlbrook, Herefordshire.
The pipe had dripped bacteria into the chocolate crumb used to make a variety of chocolate bars.
The company allegedly knew about the problem since February, but fixed it without making a recall or notifying regulators.
The Health Protection Agency subsequently found a direct link between a salmonella outbreak affecting 37 people and the Cadbury chocolate.
The Health Protection Agency said interviews with 15 of the 37 people affected by an outbreak of Salmonella montevideo last year indicated that 13 of them reported eating products made by Cadbury.
The HPA also confirmed that samples taken from Cadbury's factories showed the same Salmonella montevideo was present in January and February.
The dates of the outbreak in the population was from February to June.
The HPA also noted the decrease in the frequency of cases of Salmonella montevideo following the company's recall of a number of its chocolate products.
The HPA reported the company had discovered that waste water from a plant in Herefordshire had dripped down into the milk chocolate crumb, a mix that is blended with other ingredients to make some of the company's chocolate bars.
The pipe was fixed but despite finding the Salmonella pathogen in some of its products, the company allegedly failed to make a recall at the time.
Cadbury claimed in a subsequent press release it did not disclose to officials that its products could be contaminated with the Salmonella montevideo strain as only 'minute' traces of the bacteria were found and the company deemed the risk too low.
The Advisory Committee on the Microbiological Safety of Food (ACMSF) released a damning report in July 2006 in which it stated that: "The presence of salmonella in ready-to-eat foods such as chocolate is unacceptable at any level."
The ACMSF also said that the company failed to correctly implement EU-wide guidelines laid down by international food safety codes, known as Hazard Analysis and Critical Control Point (HACCP) analysis.
New EU hygiene directives came into force at the start of this year, embodying HACCP principles in the bloc's law.
"Cadbury's risk assessment does not address the risk of Salmonella in chocolate in a way which the ACMSF would regard as a modern approach to risk assessment," the ACMSF stated.
The findings of the report, published by the UK's Food Standards Agency (FSA), concluded that Cadbury had used methods of product testing that were likely to underestimate the presence of the bacteria.
A negative result from the tests would not necessarily mean that the product was uncontaminated.
"Based on the information provided, Cadbury appears to have used methods for product testing which the committee considered would underestimate the level and likelihood of salmonella contamination," the advisory committee stated in its report.
"Sample heterogeneity including clumping of bacteria will influence the MPN (most probable number) estimate and therefore the approach cannot be relied upon in foods such as chocolate."
HACCP is a science based and systematic method of identifying specific hazards and measures for their control to ensure the safety of food.
Its basic principles rest on establishing control systems that focus on prevention rather than relying mainly on end-product testing.
Following a meeting with the FSA in July, Cadbury agreed to undertake 'remedial action', which would involve changing cleaning regimes in the plant and stepping up testing for a wider range of products.
In a statement, Cadbury Schweppes said it was "moving to a protocol in which any product evidencing contamination is destroyed."
According to the FSA, Cadbury has pledged to carry out a positive release system whereby products will only be released for consumption if they test negative for the salmonella bacteria.