How to approach this email

[ChroniC]

I am stuck between a rock and a hard place and need a bit of advice.

I work as a freelance image editor and designer, I obviously have to keep my clients happy to keep them as clients, however one who pays me a decent sum each month is kinda taking the proverbial.

Here's the example. I set an agreed rate for a service. The service is based on a timescale i.e Images per hour. This was set based on examples given to me at the beginning of the agreement, however the client has now started sending sub par work and I need to email him telling him his work is taking to long to complete based on the current rate.

I often suffer a lack of tack and would like some advice on telling someone who you want to keep sweet that they need to either do better or get charged more, without them thinking of looking elsewhere.

Any ideas.
Thanks.

 

[ChroniC]

Sadly it's not written in a contract, but yes it was agreed that when given a few of the sample batches that it could be done within a timescale of an hour. Currently taking nearly double that.

I can afford to lose the client, but I would rather not. So am going to present the problem to them and hope for the best, I just need a lesson in how to do that tackfully.

 

[ChroniC]

Think I shall take the phone route. My customer call me a lot, and I am very informal with most, so writing letters would be very out of place.
Lesson learnt really that I need to have some sort of safeguards or signatures on something somewhere so that I can be more ruthless.