Are there any circumstances where it is acceptable not to follow through on tasks or commitments, you have said yes to?

Here are some circumstances where it may be acceptable...

• You agreed to the task or commitment under coercion.
• You agreed to the task or commitment, without thinking things through.
• The task or commitment involves a commitment of money (or money and time) from your side, that you have changed your mind about, and have decided you do not want to make.
• A gut feeling surfaces, that the task or commitment, is not the right thing to do, or not right for you.
• You have learned new information, which rules against doing the task or commitment. 
• Something has arisen - such as a health issue, or a personal crisis, which is a legitimate reason for you not to follow through:

In all of the above circumstances, it is important to let the person or people you are letting down, know.

Better still, do not commit.

Better to say you can't make a commitment, then to make a commitment, and back out.

Because think about it...

Saying yes, and then backing out, can cause an inconvenience.

It can cause financial loss.

It can cause physical difficulty.

It can cause the person to scramble to make alternate plans, to fill the spot you have created.

This is, of course, besides making them feel disappointed, making them feel let down.

So, whatever you do, do not make backing out of commitments a habit. 

You don't want to develop the reputation of being a flake.

You don't want to develop the reputation of being an opportunist. 

An opportunist says yes, but keeps their options open.

If something better comes along, they casually back out of the commitment, often giving a lame excuse about why they had to back out.

Much better to RSVP no, even if it means losing your place, and the opportunity to change that.

It's no secret...

Relationships and friendships are strengthened, when those in the relationship or friendship keep their word, and keep their commitments.

When you shake hands on something, make your handshake firm.