If you find your credit score to be way below the requirements for the pay monthly contract, there are few ways to repair it and improve it.
There are a number of ways with which you can damage your credit score. The most obvious one is mission your bill payments. Of course, it missing payments are not the only thing that is damaging to your credit score, you should also look after these:
Data is not up to date
If you have a debt showing as outstanding and you know you have paid it off, you should contact the provider involved and have them correct this.
There are inaccuracies in your credit report
You should be wary of identity thefts and frauds applying for credit in your name. If you see an item you don't recognize, contact the provider and ask them to investigate and correct the problem.
Don't use joint accounts
It is seldom a good idea to have a joint account with your partner. Being financially tied to someone means that their credit rating will affect yours as well. That means, if they have a low credit rating, you won't be able to get a mobile phone contract or a mortgage. Also, if you are no longer living together, you should contact the provider and break this link.
Be a borrower
Not having a credit history can be equally problematic when you apply for a contract phone to having a bad one. The reason for this is that the retailer or network won't have anything to base their decision on.