Just about to import a few sports cards worth around £800 to Thailand

Anyone know the charges I would have to pay as 7% isn't too bad but don't want to get hit with much more.

The 7% you mention is probably the Value Added Tax (VAT)

 

For customs duty, use the tariff number 4911.99.40

The website 

http://itd.customs.go.th/igtf/en/main_frame.jsp

shows a rate of 40% for. This is calculated on the Landed Cost:

       Value of the goods

    + Freight (eg postage fee)

    = Landed Cost

 

The VAT is calculated on the Landed Cost

14 minutes ago, Puccini said:

The 7% you mention is probably the Value Added Tax (VAT)

 

For customs duty, use the tariff number 4911.99.40

The website 

http://itd.customs.go.th/igtf/en/main_frame.jsp

shows a rate of 40% for. This is calculated on the Landed Cost:

       Value of the goods

    + Freight (eg postage fee)

    = Landed Cost

 

The VAT is calculated on the Landed Cost

That is the HS code for printed license keys for computer software. And the 40% is the ceiling rate, the general rate would be exempted (0 in practice)
Trading cards fall under HS code 4911.1090. Ceiling rate is also 40% but the reduced general rate is 10%. 
Op will have to pay 10% import duty in the cards plus shipping plus insurance, and then 7% on the cards plus shipping plus insurance plus import duty. 

1 hour ago, Gulfsailor said:

That is the HS code for printed license keys for computer software. And the 40% is the ceiling rate, the general rate would be exempted (0 in practice)
Trading cards fall under HS code 4911.1090. Ceiling rate is also 40% but the reduced general rate is 10%. 
Op will have to pay 10% import duty in the cards plus shipping plus insurance, and then 7% on the cards plus shipping plus insurance plus import duty. 

 

Thank you for this clarification,