sending numerous prove it letters to same company

[Mummyj87]

So I have apperently several debts with lowell. Can I just send 1 prove it letter and list the numerous reference numbers or do I have to send a seperate one for each?

Figured i'd ask since it's recommended I send them recorded and that'll probably be fairly costly. Thanks

[Amethyst]

If the 'prove it' letter is actually a formal CCA request ( with a £1) you will need to send individually for each account - but if it's just general then all in one is fine.