Credit scores move on evidence, not promises. The good news: the evidence that moves them is mostly boring, free and within your control. The honest news: the fastest meaningful change takes about three months, because that is how long a clean pattern takes to look like a pattern.
The moves that work, in order of effect
1. Pay everything on time, starting now. Repayment history is the heavyweight on an NZ credit file. Set every credit account, card, loan, buy now pay later, to an automatic payment the day after payday. One month of all-green is a start; three months is a visible trend; twelve is a different borrower.
2. Fix any unpaid defaults. An unpaid default is the single ugliest thing on a file. Paying it does not erase it, but a default marked paid reads very differently to a lender than one still sitting open. If you dispute it, raise a correction with the bureau; wrong defaults happen and they are fixable.
3. Get card balances under control, and keep limits honest. Cards sitting near their limit read as strain even when payments are on time. Pay the balances down, and if a card exists only for the limit, cut the limit. If the balances will not budge, a debt consolidation loan turns revolving strain into one fixed repayment with an end date, and our guide on paying off card debt faster covers the no-loan routes too.
4. Stop applying for things. Every credit application can land a hard enquiry, and a burst of them drags the score at exactly the moment you want it strong. Shop with quote enquiries instead; the difference is the subject of our guide to quote enquiries versus hard enquiries.
5. Check your file for errors. Request your own file from Centrix, Equifax and illion, free. Look for accounts that are not yours, defaults that were paid but show open, and old addresses tangled with someone else’s file. Corrections cost nothing but a form.
What does nothing
Closing every account you own (a thin file scores worse than a clean active one), paying for “credit repair” that just sends the dispute forms you could send free, checking your own score obsessively (harmless, but it is a scoreboard, not a lever), and moving debt in circles between products without the balance falling.
The three-month rebuild
If a lender has just said no, the highest-value plan is usually: automatic payments on everything, settle or arrange any open default, card balances down and limits trimmed, zero new applications, then reassess. Three months of that changes what the panel offers, and sometimes it changes a no into a yes at a rate you can live with.
When you are ready to see what your file prices at, check your rate once, properly, with every cost shown, and decide with the numbers in front of you.