In other words, different tests are applied when it comes to look for evidences regarding terms implied in fact and terms implied in law. Two tests are applied to terms implied in fact: business efficacy and officious bystander tests. Two tests are applied to terms implied in law: type of contract and necessity tests. All of these tests are completely different from each other, and they serve as guidelines at the time of finding evidence in relation to the characteristics of the terms.
Koffman and Macdonald establish the difference between both kinds of terms as follows: "Terms implied in fact are individualised gap fillers, depending on the terms and circumstances of a particular contract. Terms implied in law are in reality incidents attached to standardised contractual relationships" (Society of Lloyds v Clementson  CLC 117, Steyn LJ at 131 in Koffman and Macdonald, 5th ed.).
On the other hand, David Atkinson from Client Plus (1999) and Gillhams Solicitors & Lawyers (2005) deal in separate publications with the issue of implied terms from a general point of view. Their conclusions are similar when they explain the different elements that are necessary for a term to be considered as implied. Atkinson quotes His Honour Judge Thayne Forbes QC enumerating five elements in the case of Davy Offshore -v- Emerald Field Contracting (1991) 55 BLR 1. These five basic points are the following in order for a term to be implied:
(1) it must be reasonable and equitable;
(2) it must be necessary to give business efficacy to the contract, so no term will be implied if the contract is effective without it;
(3) it must be so obvious that it goes without saying';
(4) it must be capable of clear expression;
(5) it must not contradict any express term of the contract.'" (Atkinson, 1999; Gillhams, 2005).
Asif Tufal (2005b) in the Contract Law Page entitled "Terms of the Contract" published in LawTeacher.Net makes a classification of implied terms as follows:
1.- Terms Implied by Custom:
"The terms of a contract may have been negotiated against the background of the customs of a particular locality or trade. The parties automatically assume that their contract will be subject to such customs and so do not deal specifically with the matter in their contract. See: Hutton v Warren (1836) 1 M&W 466." (Tufal, 2005b).
2.- Terms Implied by the Court:
These terms are classified into two types of implied terms: terms implied as fact and terms implied by law following the next criteria:
A.- Intention of the Parties/Terms Implied as Fact.
Tufal makes the following assertions about the two different tests that are applied to terms implied as fact: In relation to business efficacy, Tufal explains that "The courts will be prepared to imply a term into a contract in order to give effect to the obvious intentions of the partie (.) the court will supply a term in the interests of 'business efficacy' so that the contract makes commercial sense. See: The Moorcock (1889) 14 PD 64." (Tufal, 2005b). Regarding the "officious bystander", Tufal states that "A more recent test is the 'officious bystander test' used to incorporate implied obvious terms (Shirlaw v Southern Foundries  AC