why my card suddenly invalid?

Hi

Follow the instructions here as appropriate, including checking that your address details fully match those on file with your card issuer / bank:

• Pay an unpaid balance in the iTunes Store - Apple Support
• Change or remove your Apple ID payment information - Apple Support
• Payment methods you can use in the iTunes Store, App Store, and iBooks Store - Apple Support

You may also wish to check with your bank (in case it has declined Apple's payment authorisation requests).

If you still need help, contact iTunes Support:

Contact - Official Apple Support

(I'm afraid that no-one here can access your account to advise you of the reason for your billing issue. This is a user-based technical support community - you are not talking to Apple here).

iezs54 wrote:

before this all doing fine now its invalid why!!

What card?

Before what exactly?

Hi

Check end date on your card?

Have you got a new card?

Cheers

Brian

No-one here can tell you what the problem is - see my previous reply and follow Apple's instructions in the linked support articles, including contacting iTunes Support if necessary.