Getting quotes you can compare
Three quotes are only useful if they describe the same work. Write a short brief once, send it unchanged, and keep the replies together.
The lowest number is often the quote with the most exclusions. Read those lines before you rank the totals.
Write the brief
Include the address, what is wrong or what you want built, what must stay, and any product you have already chosen. Add photos. Say whether you want supply and install or labour only.
If the job needs a licence, say which state or territory the property is in. Ask each business to put their licence number on the quote.
Read the reply
Check the business name against the ABN or NZBN, and the licence against the register. Check inclusions, exclusions, how long the price lasts, and how a variation will be approved.
A deposit should be explained. Progress payments should match work you can see, not a single date on the calendar.
Decide
Choose the quote whose scope you understand. If two totals are far apart, ask each business what the other might have left out, without handing over the other firm's price as a target to beat.
When you accept, the drawings or the brief you agreed should be named in the acceptance. A handshake plus a text message is a weak record.
Common questions
How many quotes do I need?
Two is a start. Three is easier when the job is large or the first two scopes do not match. One quote is enough only when you already know the scope and the business.
Should I tell them the other price?
You can say another quote is higher or lower. Giving them the other firm's number invites them to trim the scope rather than explain the difference.