It is LEGAL to carry a firearm into private businesses with "No Weapon" and "No Firearm" signs.
These signs Do Not have the force of law, but businesses may have policies that can restrict a person from carrying a firearm. When going in businesses with these signs and carrying a firearm, either open or concealed, you are ignoring the property owners policies. If you are asked to leave by the owner or any employee of the business, you must leave. If you refuse to leave you could be charged with criminal offenses such as criminal trespass and/or disorderly conduct. Always be aware of the possibility that responding law enforcement who may have been called without your knowledge could arrest you even if you are within the law.
Businesses or private property owners, such as the Megaplex movie theaters, who knowingly allow a person who has a permit to carry a concealed firearm onto the owner's property is not civilly or criminally liable for any damage or harm resulting from the discharge of the firearm by the permit holder while on the owner's property. If you click on the image to the left you will see that the bottom of the sign reads "Except persuant to UCA Section 53-5-701". U.C.A. 53-5-701 is the Concealed Firearm Act and "et seq" means "and what follows" meaning what the Act says.
This means businesses that do not post signs or post signs prohibiting weapons or firearms but who allow concealed firearm permit holders to carry their firearms cannot be sued or charged with a crime if the permit holder discharges their firearm.
If the property owner solicits, requests, commands, encourages, or intentionally aids the concealed firearm permit holder in discharging the firearm while on the owner's property they are liable.
76-6-206. Criminal trespass.
(1) As used in this section, "enter" means intrusion of the entire body.
(2) A person is guilty of criminal trespass if, under circumstances not amounting to burglary as defined in Section 76-6-202, 76-6-203, or 76-6-204 or a violation of Section 76-10-2402 regarding commercial obstruction:
(a) the person enters or remains unlawfully on property and:
(i) intends to cause annoyance or injury to any person or damage to any property, including the use of graffiti as defined in Section 76-6-107;
(ii) intends to commit any crime, other than theft or a felony; or
(iii) is reckless as to whether his presence will cause fear for the safety of another;
(b) knowing the person's entry or presence is unlawful, the person enters or remains on property as to which notice against entering is given by:
(i) personal communication to the actor by the owner or someone with apparent authority to act for the owner;
(ii) fencing or other enclosure obviously designed to exclude intruders; or
(iii) posting of signs reasonably likely to come to the attention of intruders; or
(c) the person enters a condominium unit in violation of Subsection 57-8-7(8).
(3) (a) A violation of Subsection (2)(a) or (b) is a class B misdemeanor unless it was committed in a dwelling, in which event it is a class A misdemeanor.
(b) A violation of Subsection (2)(c) is an infraction.
(4) It is a defense to prosecution under this section that:
(a) the property was at the time open to the public; and
(b) the actor complied with all lawful conditions imposed on access to or remaining on the property.
76-9-102. Disorderly conduct.
(1) A person is guilty of disorderly conduct if:
(a) the person refuses to comply with the lawful order of a law enforcement officer to move from a public place, or knowingly creates a hazardous or physically offensive condition, by any act which serves no legitimate purpose; or
(b) intending to cause public inconvenience, annoyance, or alarm, or recklessly creating a risk thereof, the person:
(i) engages in fighting or in violent, tumultuous, or threatening behavior;
(ii) makes unreasonable noises in a public place;
(iii) makes unreasonable noises in a private place which can be heard in a public place; or
(iv) obstructs vehicular or pedestrian traffic.
(2) "Public place," for the purpose of this section, means any place to which the public or a substantial group of the public has access and includes but is not limited to streets, highways, and the common areas of schools, hospitals, apartment houses, office buildings, transport facilities, and shops.
(3) The mere carrying or possession of a holstered or encased firearm, whether visible or concealed, without additional behavior or circumstances that would cause a reasonable person to believe the holstered or encased firearm was carried or possessed with criminal intent, does not constitute a violation of this section. Nothing in this Subsection (3) may limit or prohibit a law enforcement officer from approaching or engaging any person in a voluntary conversation.
(4) Disorderly conduct is a class C misdemeanor if the offense continues after a request by a person to desist. Otherwise it is an infraction.
53-5-704. Bureau duties -- Permit to carry concealed firearm -- Certification for concealed firearms instructor -- Requirements for issuance -- Violation -- Denial, suspension, or revocation -- Appeal procedure.
(3)(b) The bureau may not deny, suspend, or revoke a concealed firearm permit solely for a single conviction of an infraction violation of Title 76, Chapter 10,Part 5, Weapons.
This means that even if you are convicted of a single infraction, you will not lose your concealed firearm permit.
53-5a-103. Discharge of firearm on private property -- Liability.
(1) Except as provided under Subsection (2), a private property owner, who knowingly allows a person who has a permit to carry a concealed firearm under Section 53-5-704 to bring the firearm onto the owner's property, is not civilly or criminally liable for any damage or harm resulting from the discharge of the firearm by the permit holder while on the owner's property.
(2) Subsection (1) does not apply if the property owner solicits, requests, commands, encourages, or intentionally aids the concealed firearm permit holder in discharging the firearm while on the owner's property.