I have just remembered that I need to change something – do I need to pay again?

With Order (M)SDS:

You have 10 extra revisions free of charge from the moment you’ve ordered your (M)SDS to update it.

With Create (M)SDS:

You can make as much changes as you want to free of additional charges. You are only paying 2 year subscription for every created (M)SDS.

Further reading:

How do I create (M)SDS?

How am I charged for create and order (M)SDS services?

The difference between create and order (M)SDS

What do you mean by a 100% RISK-FREE guarantee?