UK customs requesting invoice

[J4G3D]

Hoping someone could share some info here on an undervalued customs invoice. It's for a bunch of 60 items mostly all the same that I plan to resell.

They are requesting

1. If it's personal or business
Q what are the pros and cons of choosing either?

2. Revised invoice
Q could I just modify an Alibaba invoice?

3. Provide proof of payment.
Q whats the safest method of showing this without them checking.

Thanks

[agent006140]

How much did you underdeclare those 60 items?

[J4G3D]

Originally Posted by agent006140

How much did you underdeclare those 60 items?

3800 maybe

But they aren't items that are common.