u/Ok-Neat-4410

I've been an artist/designer for 4 years now but I started off self employed selling my own work and now I'm full time in house but have started doing some freelance retainer bits on the side.

I landed a new client which I'm really excited to work with and they have me on retainer with an agreed upon fee per month.

The first month I did work for them was half way through so I charged them half of the fee, they missed the deadline on the invoice (I send them through stripe) but they emailed to say it was because they process pay on Fridays and to try send invoices that land on Fridays moving forward. No worries.

This month I send an invoice on the first which was a Friday and it timed out Friday the 8th, it's still unpaid. I send a follow up email today asking for some clarification as to why it hadn't been paid yet.

Do you guys have any advice? I'm not sure the best way to go so it chasing invoices as it's a new concept to me. Should I charge late fees? Do I just keep emailing asking? They're a large UK wide company so I don't feel as bad chasing them compared to if it was a smaller place

Any advice is helpful!!