A recent post on the Texas Association of Realtors® responded to the question of whether or not a buyer could require a that certain company or certain professional be used to make repairs the seller agreed to have done. The response was that the buyer is not allowed to make that stipulation.
The buyer is protected, however, because the current version of the residential contract does specify that repairs must be done by someone who is licensed do to the repairs, or if a licensed professional is not required for the type of work under consideration, that the repairs are done by someone who is commercially engaged in that repair business.
Basically, if the job requires a licensed electrician, the work must be done by a licensed electrician. For those repairs not requiring a licensed professional, the contract requires the repair to be done by someone other than your uncle, your friend, or you the seller, unless they have a business regularly engaging in that type of repair.
As an alternative to the seller contracting for repairs, buyers may consider asking for an adjusted sales price allowing the buyer to hire repairs done after closing. Some buyers prefer this so that they have more control over which company is hired and in order to have a relationship with the company should more work be required. There can be benefits to the seller in lower closing costs as well.
If the repairs are something required by the lender, however, lender approval may be required. With estimates provided by licensed and/or professional tradesmen, most lenders will allow an amount of cash equal to the repair cost(s) to be put in escrow with the title company to pay for those lender-required repairs after closing. This alternative could also be available to the seller who agrees to fund repairs but wants to fund them out of seller proceeds at closing.