No, the City of Colleyville does not require that a permit be obtained for a residential garage sale.

Yes, commercial garage sales are considered a special event and therefore will require a Special Event Permit obtained through the Building Inspection Department.  Please allow five (5) to seven (7) business days for this review process.

Garage sales are permitted for not more than 10 days per year, per premises.

Yes.  The following is an excerpt from the City of Colleyville's Land Development Code, Chapter 7 - Sign Regulations, Section 7-190:

D.  Garage Sale Signs - The purpose of a garage sale sign is to announce the sale of household possessions.  Garage sale signs shall be allowed in any zoning district in accordance with Table 7-4.  The maximum area, height, spacing and setbacks of a garage sale sign shall conform to the specifications contained in Table 7-5 and shall comply with the following additional regulations:

1. Duration: A garage sale sign shall not be posted more than twenty-four (24) hours prior to the beginning of the sale and shall be removed within twenty-four (24) hours following the end of the sale.
2. Illumination: A garage sale sign shall not be illuminated
3. Permit: No permit or fee shall be required for any garage sale sign.
4. Single-family residential on-premises: One garage sale sign per street frontage shall allowed, but only on the premises where the garage sale is being conducted and where there is an existing residential use.
5. Neighborhood-wide garage sales: Two garage sale signs per subdivision entrance shall be allowed for a neighborhood-wide garage sale sponsored by a homeowner's association (HOA).  The garage sale sign may be off-premises from where the actual garage sale is conducted, but the sign shall be located on property, including a street right-of-way, that is within the limits of the homeowner's association.  The HOA must be registered with the Colleyville Code Enforcement Department.